Today's stock Ubuntu kernel update has fixed the flicker for me. No need for any GRUB workarounds.
$ uname -a Linux home 5.15.0-40-generic #43-Ubuntu SMP Wed Jun 15 12:54:21 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
So bug #1970426 is officially fixed.
Today's stock Ubuntu kernel update has fixed the flicker for me. No need for any GRUB workarounds.
$ uname -a
Linux home 5.15.0-40-generic #43-Ubuntu SMP Wed Jun 15 12:54:21 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
So bug #1970426 is officially fixed.