I understand your conviction that the issue must be caused by the rom, but flashing custom rom is very tedious thing sometimes this kind of issues tend to happen, I guess you have to provide logs to get the root cause, untill then if another rom works for you then I suggest you use it better. Don't get me wrong here friend I can relate what you are going through.
I hope there's no need to ask but I guess you have already tried clean installing the rom, or it would be slightly better if you can explain what was your flashing method, or your whole setup like device encryption, recovery, etc. May be I can help or someone else might.
Hope you're getting what I mean let me know if there's any confusion.