Foreword: As written at the Waveshare site, LE is not supported. You are experimenting on your own risk.
That display needs some software settings. You can only use the dtoverlay line at config.txt. All HDMI options have to go to cmdline.txt, which needs a different syntax.
Which of the above settings do you currently have in use for your 5 inch display?
**** List of PLAYBACK Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 [HifiBerry DAC HiFi pcm5102a-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0
The output shows a DAC chip (PCM5102A), which you don't have. Your board has a digital-to-digital chip.
I think your HiFiBerry Digi2 Pro is broken. It's not detected correctly by HiFiBerryOS.
My solution was powerline ethernet.
Yep, or an Ethernet to WiFi adapter. The newer models have 5GHz support now. Benefit: Only Ethernet driver needed.
Thanks for testing! I'm referring to this thread. Can you downgrade to LE 10.0.1? That worked for the other guy.
I've just found an extra option, which you can try at config.txt:
force_eeprom_read=0Use these two lines at config.txt:
force_eeprom_read=0
dtoverlay=hifiberry-digiCraziest workaround since many moons! 
On LE 11...
Theory: HiFiBerry driver has been updated since newer LE versions, so it's not working with your clone anymore.
Solution: Buy an original HiFiBerry soundcard. They are working fine on LE since many years.
Before buying a new soundcard, you can try Raspberry Pi OS with Kodi. If it's also not working there, my theory is confirmed.
I dont know which instructions you are talking about in Raspberry PI OS.
The hardware package has to have some instructions for driver installation. That's what I wanted to see.
It seems to use the HiFiBerry driver, but the soundcard is a HiFiBerry clone, so mysterious things can happen. 
LE's standard configuration schema is a read-only default config, and a user config, which has to be created if needed.
Read here: Samba service- query about default settings and users
I guess you're scared because of this thread: Can't connect to MariaDB server after updating to 11.0.1
You can downgrade back to LE10 any time, so just try LE11, and report.
Boot GParted Live from a thumb drive on your Windows PC, and follow plan A. Be careful.
Will this be the same on Raspberry Pi5 ??
Yes. Anything else would be a step backwards.
A license fee has to be payed for Dolby Vision, so Kodi will never support it.
Kuman SC07C Raspberry Pi HiFi Digi+ with spdif.(Soundcard)
That package contains the PiFi Digi+ soundcard, not the original HiFiBerry Digi+. So the driver at config.txt doesn't work for you.
the sudo command can be typed in raspbian session in the pi console I guess. I didnt try it so far because I dont know which commands to type.
LE doesn't support sudo, because you're already super user after login. I assume you have instructions, how to install the driver on Raspberry Pi OS (former Raspbian). Please share a link of those instructions. Maybe we can help to install that driver on LE.
I'm connecting to HDMI2.
What about HDMI-1?
