I do have the keypad sitting on a desk as I had not decided to mount it yet & the light did stay on it, but yet the other "working" V3 keypad is sitting beside it on the same desk & the lights don't stay on on it.
In fact, the "non-troublesome" V3 Keypad has been sitting on the desk for weeks & weeks now with no problem.
I did load your code for the troublesome V3 keypad & have it sitting on the same desk in the same spot now & the lights stay off...I dunno!! Maybe wife clicked heels 3 times on this one. LOL
Who knows, it may go back to "always on" in a hour or so but for now it's off (the lights) & working as normal.
Prior to loading your DEV code for it, I was just using whatever it was for this device when I "discovered" it in HE. I'll keep you posted if any changes.