Is there any progress on this? I think I am feeling the same when trying to playback Disney+. This is on a fresh install with ~/.kodi salvaged from another installation. I posted the details in another thread, Pi booting so far then black screen - #11 by NickH.
Compared to this post, I am already running kernel version 5.10.78-7-osmc so there is no point trying to revert to it.