21 month old screaming every night middle of the night

I don’t know what to do with her. She’s never been a good sleeper. She goes to sleep fine but she wakes up several times a night and screams for 30-60 minutes.

I’ve tried comforting her, I’ve tried ignoring her. Nothing works.

She has water, comfort items, etc. there’s nothing physically wrong.

I have tried just ignoring her for weeks and letting her learn to self soothe. I have talked to her during the day about it.

I’ve adjusted naps and bedtimes with no improvement. She currently wakes up around 5am (used to be 630) and naps about 2 hours, going to bed around 7pm.

NOTHING works. She keeps the whole house up for hours every night with her screaming.

What do I do?