I had the same issue the other day in the PEQ. I couldn’t get it back to 0.0db gain. It would always tick just a little more or less than 0.0.
I played around with it for a while and found that if I turned the gain all the way up or down then back to 0 I was able to get it to land right on 0.0.
I agree though, either tap/hold the button on the touchscreen to clear to 0 maybe or use .1 increments while turning when close to zero.