I also have this exact issue on my 2016 450sxf, haven't found a solution yet, should be getting the tps cables to check that out soon. Bike is solely used as a snow bike. Very unpredictable, probably had the issue here and there right off the bat, then went about 20 engine hours without a single hiccup, had an occasional problem last few rides, and last ride it seemed like it would stall more often than it would run if the throttle was chopped quickly. Results in some silly crashes on the snow bike since there isn't a way to put a foot down in a lot of places when the bike decides to stall.

Sometimes just idles really low for 10-30 seconds then returns to normal, starts and runs ok cold. If it's not the tps im thinking its got to be one of the other sensors giving a bogus output