The log shows that your USB (SSD?) drive frequently stops responding and the kernel needs to reset it (after the 30 second timeout elapsed) so no wonders you have issues playing media from it.
May 07 07:49:49.601266 RPi4 kernel: usb 2-2: reset SuperSpeed USB device number 2 using xhci_hcd
May 07 07:49:49.617935 RPi4 kernel: sd 0:0:0:0: [sda] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x03 driverbyte=DRIVER_OK cmd_age=30s
May 07 07:49:49.618535 RPi4 kernel: sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 03 3b 5d e2 00 01 00 00
May 07 07:49:49.618913 RPi4 kernel: I/O error, dev sda, sector 54222306 op 0x0:(READ) flags 0x80700 phys_seg 6 prio class 2
Insufficient power and broken cables/connectors/... are very often causing such errors, so first try to look into that and connect via a powered USB3 hub.
Lots of USB devices, especially the cheap no-name ones, have broken USB implementations and sometimes it's possible to work around those with usb-storage.quirks - in your case it's not the rather frequent UAS issue though, it's already using the usb-storage driver.
Quick search for the USB IDs (idVendor=13fd, idProduct=3456) didn't show up anything useful, searching for "sage 3639S" did neither so not sure what device you actually have.
so long,
Hias