Looks like HV fluctuations / issues - might be caused by worn out/defective consumables or bad contacts.
It's not unusual that one issue can sort of...
If you want to rip a bluray medium without re-encode there should be not bitrate option at all because the tool is suppose to rip the original stream...
If the files have insane bitrates and/or the encoding settings are out of specs (like too many reference frames) you'll probably end up with problems...