Are you sure that plugging it in to diagnostics is making them come back on or could it be just the fact that the ignition is turned on and off?
I ask because just today in the middle of a ride my aux fog lights, aux brake light, and my horn/strobe function turned off by themselves. Upon getting home I turned the bike off, immediately turned it back on and everything was working again. This is the first time its happened in this way. But as you see in another post I made this week, I have had the aux lights not come on when starting the bike but can toggle them with the directional light switch and they will come on again.
I must say, I am losing confidence in the system because of these glitches. I hope someone can address our issues.