I've been having issues with my terrova, happens probly 10 times a day, that the head unit won't respond to the buttons I push on my ipilot remote. Tried a fresh battery. It always has full signal strength when it happens as well. Today I actually had to run up there and unplug it because I was turned and it was just spinning circles. Got a lot of funny looks from neighboring boats on that one lol. Usually I keep pushin the button and after 5ish seconds it finally responds and will run like normal for a wile then randomly happen again later. Kinda getting irritating
Mine will on occasion do this also, and like you I just unplug, and plug back in and its fine. Seems a lot of the time I have to jack rabbit start it too, just to get the prop spinning, then back it down to the speed I am wanting.
Thing is almost 10 years old, so it owes me nothing.