Not sure if it’s entirely linked but I have found chapter skipping to be quite wonky on most occasions. Skipping to the next chapter often just freezes up the video and then I have to press short-forward or short backward (10 secs) for it to unfreeze. Sometimes it works as intended. I have mentally made peace with this behavior so it doesn’t bother me as much.
It doesn’t happen with all videos but still happens quite frequently. Not sure if whether the way chapters are muxed into a video is the culprit or if it’s Kodi related…
Is this a UHD remux?
UHD remuxes don’t store chapter markers on key frames. There’s a patch for this which we had in v17.6, but I seem to recall this causing an issue in v18.4.