That sounds like you really have mixed/complex sleep apnea, because of the high number of centrals. At least you're not on CPAP/APAP.
Depending on how much your values vary, that may be simply part of the central apnea - it's consistently inconsistent. Two nights ago I had an AHI of less than 9. Today I was at nearly 30. (I'm still waiting for admission/tests to get ASV hopefully and my central apnea is rampantly out of control).
You might want to go here:
https://www.apneaboard.com/wiki/index.ph...ganization
This will help you arrange your charts in a way that we get the most information. It would also help if you could scroll down on the left-hand side and ensure we get a full copy of the statistics too.
It can sometimes take a couple of months or more to feel really good, but it's going to depend on what symptoms you had and underlying health issues. What symptoms are you still getting, and has anything improved since you started? Are there any other underlying health issues that might be exacerbating your symptoms too?
Hopefully, some of the others with a little more experience of BiPAP will be along soon and might be able to suggest something. If you haven't already worked it out, the UAs are probably centrals.