I want to force the system to use these specific EDID files on each HDMI port. Can you explain why this should be removed, or should it be placed in a different place now?
"Eventually". It's just for testing. If removing one of those lines solves the problem, then we narrowed down the issue.
The TV is directly in the HDMI Port beside the Power Supply Port.
That's right.
Next I would try another HDMI port on TV (if numbered, then usually the first one works best).
Also check whether your HDMI cable has HDMI 2.0 or 2.1 standard. A bad cable is often the cause when users don't get video.
Given that the config.txt entries are ignored in this case, could you please confirm whether audio output through HDMI1 is the default behaviour?
The default audio device is defined at the LE audio settings. Both HDMI ports are able to play audio.
I assume that apart from specifying video=HDMI-A-1:1920x1080M@60D in the cmdline.txt file, I don’t need anything additional, correct?
Yes, but I would comment out disable_overscan=1 at config.txt to get full screen video. Eventually you also have to comment out those lines:
drm.edid_firmware=HDMI-A-1:edid/jvc.bin,HDMI-A-2:edid/sony-pure.bin
initramfs edid.cpio 0x3c00000Is the RPi connected to the first HDMI port (the one beside the USB port)?
Note that 'kernel param' settings in cmdline.txt are completely different from old-style config.txt settings. If you put the old-style settings in the wrong file the board probably doesn't boot.
Yep.
modedb default video mode support — The Linux Kernel documentation
Remove all HDMI settings from config.txt. HDMI settings belong to cmdline.txt now.
So I just wanna confirm libreelec and pi5 will not allow 2 HDIM ports simultaneously?
That's correct for A/V streams. Simultaneous audio is possible by using a custom LE image.
As mentioned the mini PC is not connected to its final destination TV. Do I have to repeat this HDMI setup again once it is connected there?
"Preferred setup" means "final destination", so yes.
As I can read here in the wiki, audio has to work. As the device is currently connected to a standard monitor without speakers, I wonder if this may contribute to all the issues?
If LE /Kodi can't find any audio output device, then I guess it's possible that issues like yours appear.
How and where can I fix that? The mini PC provides 2 HDMI ports. I tried both but no difference in behavior.
Connect your preferred HDMI setup. Then execute getedid delete, followed by getedid create on SSH terminal. Reboot.
Any more questions, or can I mark this thread as resolved?
I also wasn’t able to get the Digi+ Pro working on Raspbian.
Then it's not our fault. Ask at the HiFiBerry forum. Maybe the soldering trick also works for RPi5 (post #4), but we don't know.
I think HiassofT is right - it's very likely a hardware issue. Have a look at your Digi2 Pro board. If it has HW 2.1 printed, then you have to solder, or ask HiFiBerry for a replacement:
Take another microSD, install Raspberry Pi OS on it, and test Digi2 Pro with it. So we can figure out whether it's a general problem, or just an LE issue.
Unfortunately there is no way to change playback speed. You can only adjust the time difference between audio and video. If not already done, disable the "Sync Playback to Display" option.
Second line was like this and I keep it:
Codedtoverlay=hifiberry-digi-pro
Please use my suggestion. This is what we support:
Do you have these two lines at config.txt?
force_eeprom_read=0
dtoverlay=hifiberry-digiIf yes, and the issue remains, post a log...
Here is a log file from streaming on a clean image of 13.0 20251117 nightly. Interestingly, the glitch is not present on this version.
Thanks, it has the same errors as seen at post #3, so my theory is wrong. 
This could be the cause of the issue:
2025-11-01 10:48:10.479 T:1208 info <general>: CDVDVideoCodecDRMPRIME::Open - using decoder V4L2 mem2mem H.264 decoder wrapper
2025-11-01 10:48:10.479 T:1208 error <general>: ffmpeg[0x212e50a0]: [h264_v4l2m2m] Could not find a valid device
2025-11-01 10:48:10.479 T:1208 error <general>: ffmpeg[0x212e50a0]: [h264_v4l2m2m] can't configure decoder
...
2025-11-01 10:48:10.540 T:1214 error <general>: ffmpeg[0x209fd8f0]: [deinterlace_v4l2m2m] Could not find a valid device
2025-11-01 10:48:10.540 T:1214 error <general>: ffmpeg[0x209fd8f0]: [Parsed_deinterlace_v4l2m2m_0] Failed to configure output pad on Parsed_deinterlace_v4l2m2m_0
2025-11-01 10:48:10.540 T:1214 error <general>: CDVDVideoCodecDRMPRIME::FilterOpen - avfilter_graph_config: Invalid argument (-22)