The LFO destination menu is just sensitive encoders. I notice it sometimes. Not related to the engine hardware bug. happens on my rytm mkii and my friend’s A4mkii they have the sensitivity too high need to decrease the velocity sensing methinks. subtle things that they’re getting used to with the new encoders. The thing is some knobs have fewer values and some have tones of values so they seem to scale the encoders function by function which means lots of replicated code is my guess if you find one that doesn’t work they can’t just universally say scale all the encoders down 10% because each one is operating in it’s own scale. there’s some functions on the rytm mkii that blaze through each value in a 1/8th turn even when moved slowly. It can be frustrating but it’s nothing to worry about.
As for the sound browser coming up when doing function moves. double check your Level/Data encoder (just above the function knob) wasn’t bumped by a finger. Function plus that knob will bring up the sound browser window so it’s not out of the realm of possibility that your encoder is sensitive too and it’s sending a false positive for motion while you’re holding FUNC down. easy was would be to just use the hell out of the thing. I found mine did it less and less as you wore the parts in. I had one sticky key too but it broke in after about 2 weeks of heavy use. Glitches seem to be the indicator of hardware faults haven’t had any of that yet but glad to see yours was replaced. 