I don't have this problem on any of my 4 QMX, so I'm pretty sure it's not just firmware.
Some ideas/possible fixes:
1) I would touch up the soldering on that encoder and its connectors to the main board, in case there is a cold solder joint that causes some intermittent when you put pressure on it.
2) It is also worthwhile noting that, unlike the other QMX switches, the signal line from this switch has a more complicated connection to the processor input.? Its pullup resistor is on the 5V SMPS card, which is connected to the switch via two sets of soldered-on connectors - so any flakiness in that path could cause a problem.? Also, its connection to the processor is not direct like the others, it goes through a FET switch (Q202), which has two associated resistors (R202, R209).? One person I helped several months ago had an assembly fault in R202 (it was dislodged), which caused the problem.
3) It is also possible you just have a poor encoder part, whose switch is more bouncy.?
?
I would check those things to see if you can resolve your issue.
Stan KC7XE
