The only unusual thing that I see in the log is related to time/timing:
As RPi4 lacks an RTC time starts at the libc release date and then after the network is up NTP syncs the clock, so there's an initial large time jump forwards:
Jun 26 04:44:46.980327 Bedroom4 connmand[616]: wlan0 {add} address 192.168.86.24/24 label wlan0 family 2
Jun 26 04:44:47.071796 Bedroom4 connmand[616]: ntp: adjust (jump): +34173816.881766 sec
Jul 26 17:28:24.027154 Bedroom4 systemd[1]: Finished wait-time-sync.service.
Jul 26 17:28:24.028171 Bedroom4 systemd[1]: Reached target time-sync.target.
Jul 26 17:28:24.028457 Bedroom4 systemd[1]: Startup finished in 3.958s (kernel) + 34.148s (userspace) = 38.106s.
Jul 26 17:28:24.328811 Bedroom4 connmand[616]: Interface wlan0 [ wifi ] IPv4 online check to http://ipv4.connman.net/online/status.html succeeded
Jul 26 17:28:24.328845 Bedroom4 connmand[616]: Interface wlan0 [ wifi ] state is online
Jul 26 17:28:24.443474 Bedroom4 nmbd[874]: [2026/07/26 17:28:24.443287, 0] ../../source3/nmbd/nmbd_namequery.c:109(query_name_response)
Jul 26 17:28:24.443501 Bedroom4 nmbd[874]: query_name_response: Multiple (2) responses received for a query on subnet 192.168.86.24 for name WORKGROUP<1d>.
Jul 26 17:28:24.443521 Bedroom4 nmbd[874]: This response was from IP 192.168.86.120, reporting an IP address of 192.168.86.120.
Jul 26 17:28:25.313479 Bedroom4 systemd[1]: systemd-hostnamed.service: Deactivated successfully.
Jul 26 17:28:37.638328 Bedroom4 crond[440]: time disparity of 569564 minutes detected
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Then the next item is an SSH login:
Jul 26 17:30:01.911967 Bedroom4 sshd-session[1067]: Accepted password for root from 192.168.86.236 port 53399 ssh2
Then 3.5 mins later there's a USB device connected:
Jul 26 17:33:27.301690 Bedroom4 kernel: usb 1-1.1: new full-speed USB device number 3 using xhci_hcd
Jul 26 17:33:27.395029 Bedroom4 kernel: usb 1-1.1: New USB device found, idVendor=0d8c, idProduct=0012, bcdDevice= 1.00
Jul 26 17:33:27.395906 Bedroom4 kernel: usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jul 26 17:33:27.396525 Bedroom4 kernel: usb 1-1.1: Product: USB Audio Device
Jul 26 17:33:27.397049 Bedroom4 kernel: usb 1-1.1: Manufacturer: C-Media Electronics Inc.
Jul 26 17:33:27.405023 Bedroom4 kernel: input: C-Media Electronics Inc. USB Audio Device as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.1/1-1.1:1.3/0003:0D8C:0012.0001/input/input2
Jul 26 17:33:27.461692 Bedroom4 kernel: hid-generic 0003:0D8C:0012.0001: input,hidraw0: USB HID v1.00 Device [C-Media Electronics Inc. USB Audio Device] on usb-0000:01:00.0-1.1/input3
Jul 26 17:33:27.585045 Bedroom4 kernel: usbcore: registered new interface driver snd-usb-audio
Jul 26 17:33:27.641991 Bedroom4 (udev-worker)[1142]: event2: Process '/usr/bin/evrepeat -d 500 /dev/input/event2' failed with exit code 1.
Jul 26 17:33:27.796375 Bedroom4 Boot[1207]: ### Setting up sound card ###
RPi4 has 2x USB 2.0 ports (furthest away from Ethernet) and 2x USB 3.0 ports (next to Ethernet). The lsusb log clearly shows the DAC on Bus 001 which is the USB 2.0 bus (note the root hub type):
Bedroom4:~ # lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 003: ID 0d8c:0012 C-Media Electronics, Inc. USB Audio Device
This behaviour correlates with numerous online reports of CMedia audio devices not liking USB 3.0 ports, but in the lsusb log the device doesn't show up until the fourth connection attempt. As there are only 4x USB ports (and assuming no user error) this would imply one of the previous three attempts was also to the other USB 2.0 port and the device didn't show up. Other than user error I'd have no explanation for that.
The kodi log shows the same timezone jump; marked by a failure to find releases.json as the TLS certs are probably invalid due to the wrong host datetime, which is all normal:
2025-06-26 04:44:46.754 T:960 error <general>: SETTINGS: load_url # Error loading url: http://releases.libreelec.tv/releases.json
Reason: [Errno -3] Temporary failure in name resolution
2026-07-26 17:28:23.975 T:960 info <general>: SETTINGS: __init__ # updateThread Started
2026-07-26 17:28:23.977 T:960 info <general>: SETTINGS: set_auto_update # auto
2026-07-26 17:28:24.161 T:1039 info <general>: SETTINGS: run # Waiting
but then Kodi appears to be in a waiting state trying to find the 192.168.86.216 device:
2026-07-26 17:28:24.431 T:1040 warning <general>: CPlayerCoreFactory::GetPlayer(TV(192.168.86.216)): no such player: TV(192.168.86.216)
2026-07-26 17:28:24.572 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'FileNameAndPath'
2026-07-26 17:28:24.604 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'IsUpdating'
2026-07-26 17:28:24.604 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'NumAllItems'
2026-07-26 17:28:24.604 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'HasFolders'
2026-07-26 17:28:24.605 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'HasFiles'
2026-07-26 17:28:24.605 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'HasParent'
2026-07-26 17:28:24.605 T:958 warning <general>: [plugin.video.youtube] xbmc_context_ui:203(refresh_container) - Plugin container not found for 'FolderPath'
2026-07-26 17:28:24.606 T:958 info <general>: [plugin.video.youtube] service_runner:55(run)
Starting v7.4.4
Kodi: v21.3 (Kodi Omega)
Python: v3.11.13
2026-07-26 17:29:54.077 T:928 info <general>: Samba is idle. Closing the remaining connections
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Then finally some 1.5 mins later (3.5 mins after the initial timezone jump):
2026-07-26 17:31:24.189 T:928 info <general>: Loading controller layout: /usr/share/kodi/addons/game.controller.keyboard/resources/layout.xml
2026-07-26 17:32:21.644 T:937 info <general>: CActiveAESink::OpenSink - initialize sink
2026-07-26 17:32:21.645 T:937 info <general>: CAESinkALSA::Initialize - Attempting to open device "@"
2026-07-26 17:32:21.650 T:937 info <general>: CAESinkALSA::Initialize - Opened device "sysdefault"
2026-07-26 17:32:21.651 T:937 info <general>: CAESinkALSA::InitializeHW - Your hardware does not support AE_FMT_FLOAT, trying other formats
2026-07-26 17:32:21.651 T:937 info <general>: CAESinkALSA::InitializeHW - Using data format AE_FMT_S24NE3
2026-07-26 17:32:24.635 T:928 info <general>: Loading skin file: Settings.xml, load type: KEEP_IN_MEMORY
2026-07-26 17:32:28.789 T:928 info <general>: Loading skin file: SettingsCategory.xml, load type: KEEP_IN_MEMORY
2026-07-26 17:32:33.249 T:928 info <general>: Log level changed to "trace"
2026-07-26 17:32:33.249 T:928 info <general>: Enabled debug logging due to GUI setting. Level 2.
2026-07-26 17:32:33.250 T:928 debug <general>: ------ Window Init () ------
2026-07-26 17:32:33.312 T:950 debug <general>: PushCecKeypress - received key b duration 69
2026-07-26 17:32:38.467 T:958 debug <general>: [plugin.video.youtube] service_runner:138(run) - Clear property 'plugin_sleeping'
2026-07-26 17:32:38.601 T:958 debug <general>: [plugin.video.youtube] service_runner:244(run) - Set property 'plugin_sleeping': 'true'
2026-07-26 17:33:27.712 T:934 debug <general>: CLibInputHandler::DeviceAdded - keyboard type device added: C-Media Electronics Inc. USB Audio Device (event2)
2026-07-26 17:33:27.713 T:934 debug <general>: CLibInputKeyboard::GetRepeat - could not get key repeat for event2 (Function not implemented)
2026-07-26 17:33:27.713 T:934 debug <general>: CLibInputKeyboard::GetRepeat - delay: 400ms repeat: 80ms for C-Media Electronics Inc. USB Audio Device (event2)
2026-07-26 17:33:27.733 T:938 debug <general>: CALSADeviceMonitor - ALSA card added ("/sys/devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.1/1-1.1:1.0/sound/card2", "/devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.1/1-1.1:1.0/sound/card2")
2026-07-26 17:33:27.738 T:936 debug <general>: CActiveAE - device change event
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The reason timing stood out to me is that Kodi only evaluates its audio devices at startup (there is no hotplug support) and the logs show the DAC device, despite the long 3.5 mins stall period between timezone jump (network up, which Kodi waits for) and the DAC being connected. It's like Kodi is waiting for the DAC ??
Regardless, none of that would explain the original issue report of DAC disconnects though. The normal reasons for that would be power draw on the USB bus, or perhaps bad USB cables or issues with physical USB connectors.
So back to basics. Please go try a current LE13 nightly on a spare SD card with clean Kodi config and the DAC connected to working USB ports (which are 2.0 not 3.0) and a different USB cable. Use usbcore.autosuspend=-1 in kernel boot params in cmdline.txt again if no difference.
Pinging popcornmix to see if he has any ideas too.