According to the schematic, that is a 10k pot with a center detent. The detent is the little ‘click’ you feel when the pot it turned exactly to 12 o’clock. It makes it easier to rest the pot in the exact center of its sweep.
9mm rotary pots are pretty standard stuff, but with a center detent is a bit more rare. You could probably swap in any 9mm 10k ‘snap-in’ pot, like an Alpha or Bourns, that doesn’t have the center detent but finding the exact middle of the sweep range could be tricky.
I just had the exact same problem, it won’t stay centered and intermittently fades. Hoping to solve this as well! In the meantime, you can turn this knob off in the utilities menu if you move to memory 2-8.