Is your video using a Atmos / TrueHD audio stream by chance? If so, I'm experiencing the same issue on a Pi4. Chapter skipping results in a hard crash, 100% reproducible. If I change the audio track from TrueHD to AC3, chapter skipping works flawlessly, HD video or no. It seems to have to do with TrueHD audio decoding in my case, not video.