Pull up resistors

I am trying to do a pin change detect on Pins D0, D1, D2, D3, D4, and D5. All pins except for D5 have the pull up resistor enabled and work correctly. D5 does not. My PR setting is “FF” which I would expect to mean all of them on. And just because, I have tried FE, 7f, 80, 81… I am clueless. Any help would be greatly appreciated.

D5 does not have a pull up resistor option in the bitfield of the PR parameter.