fingerprint still by luck ! latest software.
Was having this stupid problem for the longest time.
But the latest patch improved/fixed(?) this issue for me. But I also did a few other things.
When registering the fingerprint, I registered the meaty portion of my thumb. At first, I was registering the edge near my fingernail because its more natural for me to press near the edge when i hold the phone. This led to a success rate of 1/3.
Second was the consciously force myself to press with the meaty part of my thumb instead of the edge near my fingernail. This is really a pain in the ass because it is hard to change a habit. After a month or so I more or less have gotten used to it. Now my success rate is about 9/10.
I suspect the tap to wake function may also be affecting the success rate but purely my speculation.
Slightly off-topic but when I went on holiday to a cold country with the phone, my success rate dropped to 3/10. I'm not sure if its because the lack of oiliness made it hard to read the fingerprint, but this really pissed me off so much that I had to revert to a pattern unlock instead.
My experience with pixel 6a ba....hope yours gets sorted out soon too.