Prime 4 Sweep knob & Low EQ knob

Had my P4 for one year. Never played out (lockdowns) - just practicing & uploading mixes to mixcloud/odd livestream and yet already, I have noticed how my channels 1 & 2 (esp 2) Sweep & Low EQ knobs have some give compared to the lesser used channels 3 & 4.

Still works & not a major concern and I may be worrying unduly but I am just wondering whether these knobs can be replaced should the worse happen? Will it likely be an expensive repair job?

Is a looser feel/more give quite normal & has any others observed the same?

Quite strange that my much cheaper Pioneer SB3 knobs feel like new.