Well, I can't speak for the OP, but it was a problem for me as well. I think two or maybe more rented pianos I'd had at a few places in the rock and roll days, there was literally blood on the keys. FTR, trimmed fingernails.
Just too much lateral motion, I guess, in my case. I fixed it with the awkward combination of having long fingers and needing to play closer to the fallboard for some passages, even in sloppy R&B/rock by just, well, fixing it.
No, for OP, that doesn't sound right.
Yeah, I think photos is needed, b/c if it can't be fixed by adjustment to technique, and it occurs across multiple keyboards, it's not one of those.