I’m using the latest (20250707) nightly NG build on an AM6B+, and there’s an issue playing at least one (possibly more) files that several users have observed elsewhere. It’s an issue in Kodi itself though, not CE-specific. It’s been solved in Kodi’s latest v22 nightly builds; will this ever be incorporated into NG? I’m guessing not since NO is in development… but I’m ever hopeful 
There’s a thread at Kodi detailing the issue. The start and end of it are most informative: https://forum.kodi.tv/showthread.php?tid=382140
In short: A mid-stream change in the HDR metadata causes the videoplayer to reinitialise, causing a brief black interlude in playback. Fixed by ignoring the change.