RPs get flaky after a while if you make a lot of changes to them. I think that somewhere in the RP operating system, there is a garbage collection routine that gets rid of what’s left over after a patch is edited from the front panel or from Xedit. After a while, the garbage starts to overflow, and the RP begins to do weird stuff, like changing volume levels or turning FX on or off arbitrarily.
I’m not entirely sure about the cause, but I have the cure: when your RP starts to act arbitrarily, back up all your patches via Xedit’s DEVICE/BACKUP function, then do a factory reset. When the reset is done, load the patches back in via Xedit DEVICE/RESTORE. Done.
This procedure never fails to fix all the random weird behavior that my RPs exhibit over time. It’s fast and it’s easy. Next time your RP gets flaky, backup, reset, and reload. It’s not the law, but it’s a darn good idea.