Again, experience buffering and bad sound

First go to Settings > Add-ons > My Addons

Then Program add-ons > InputStream Helper > Configure

InputStream Helper information will say what version of Widevine you have installed now.

Restore Widevine CDM Library will restore from backup if it exists.

Or Services > SlyGuy Common > Configure > Advanced

Then (Re)install Widevine CDM

Or Video add-ons > HBO Max > Configure > Advanced

Then same as SlyGuy Common.

You should restore or reinstall 4.10.2252.5 for the moment, then reboot and try to play something.