I tried upgrading a Pi 4 to 10.0.1 several times. To be sure I removed the EDID override with the getedit command before the upgrade. Version 10.0.1 keeps outputting a black screen right after the 'rainbow' boot screen. After I put the 10.0.0 image file in the update folder and reboot/install again the image returns. With 10.0.1 the TV does receive a signal but the screen stays black. I only use the main HDMI port.
I read in another thread that the old Pi 3 adapter doesn't meet Pi 4 specs. Today I received a new Pi 4 adapter but it doesn't make any difference at least for this issue.
For any issues, create a new thread in the appropriate forum section, and place log files onto pastebin or Kodi's pastebin website. Then paste the link thereof into your new thread.
Sorry can't do that. Log files contain my webdav passwords in plain text. I already had to remove links to a pastebin upload in another thread. And since you guys don't accept manually attached logs here I am pretty much stuck in the bug report process.