11.5mo Random screaming and inconsolable 3hrs after bedtime - nap schedule is futile - advice needed

My 11mo has always been… a challenging baby.

Firstborn is a dream, no issues.

She’s between dropping her second nap but after 2 weeks doing one it was clear she was overtired so we’re in a kind of - every third day she does 1, the rest it’s 2.

Wake windows are hit and miss, sometimes she’s just NOT tired yet and other days she’s clearly exhausted after a 90 minute 1st window.

The main problem and the reason I’m asking for advice/suggestions is she’s been waking the last 5ish nights after about 3hrs ABSOLUTELY screaming, trying to wrench herself upright and doesn’t stop for an hour sometimes 2.

She’ll quieten down for a minute then scream again for 5. Fall asleep in our arms for 5 then start screaming again. She’s mostly eyes shut during this and hands up over her face which is how she sleeps.

If we bring her out she’s perfectly happy and even kind of gets the zoomies, chatting and bashing stuff. I always keep the lights off and I just lie down whilst she does her thing - no flashy or noisy toys etc.

I know all the general sleep training advice, we did fuss it out a little with number one but this is just odd - it’s not a sleep cycle link thing because she does that.

Teeth is my other theory, other half thinks she doesn’t want to go to sleep, she has no interest in sleeping with either of us - I tried in desperation for some sleep but she just sits up in our bed or continues screaming. No interest in us just holding her in the nursing chair. If it was genuine pain I don’t see how she could be SO happy when she’s up.

CIO is starting to make its way onto the table as we just don’t know what to do but she cries to the point that she throws up when we’re holding her so I just don’t think it’ll end well even if I can muster the discipline to do it.

Thanks if you’ve read my exhausted ramblings to this point.

Any solidarity, help appreciated.