I already adjusted it to 35psi, which I have run for a while. Again, no conditions have changed, other than I put the wheels back on after a 2 month absence, and the problem was more pronounced than before.

Also, like I said, a bent wheel (or something to the effect of a defective wheel/tire combo) would be the obvious culprit, but I can't imagine a bent wheel getting progressively worse - it is what it is.