Could you attach a small problem file here for SB devs or others to examine please.? If there are privacy concerns, maybe PM (private message) one of the forum mods directly, pointing to this thread. You will need to zip up the file first before attaching.
Haven’t seen any changed system requirements for handling video from C12, other than improved H.264 hardware decoding.
(Not upgraded yet, so can’t offer clues/help personally).