Having this issue now - August 2024 & I have a solution (Mac version & on Adobe Creative Cloud).
I opened an image that had been sized incorrectly for my purpose, but all dimensions were locked & pixels wasn't even an option I could swap to as it is ghosted out in the drop down options:
FIX:
I ticked the "Resample" and was able to fix the issue - I could change dimensions, dpi and revert to pixels - phew!!
Hope this is helpful for others too.