possible codec problem

hello yesterday i updated my Win10N to 22H2 version. since then i dont have audio on X videos and get error messages on nius clips (see pic) in about:support shows h264 acc and hevc as unsupported. but i cant tell if this is new or not. anyway k-lite codec pack should make them supported, right? to further narrow down the problem i used edge and visited nius and twitter and both worked fine, so the problem must be firefox. so im out of ideas how to fix that. anyone can help me? my help request on reddit https://www.reddit.com/r/firefox/comments/1fs2in3/need_helppossible_codec_problem/