They all will drift when they are first turned on. It has nothing to do with the lights. They just need time to warm and stabilize. 2-3 hours is what is called for.
I turn my Dillon on when I head down to the bench. I always run it off the power supply, not by batteries - although I've tried running on batteries to see if that solved the problem.
By the time I've finished setting up, clearing anything that's on the bench out of the way, went and got the powder and primers I'm going to use out of their magazines, bullets, cases, dies I want, etc.... the scale has been sitting there warming up for probably half an hour; maybe 45 minutes. Still drifts.
And is still drifting three, four, five hours later. If coming back to pick up where I left off the next day, the scale sits there powered up all night. Still drifts.
That's just one scale; mine. But even if three hours of warming up was the magic number for it... I lack the patience for a piece of precision equipment that demands three hours to warm up and stabilize. If the Trimble's I use to do GPS surveys needed three hours to sufficiently warm up and stabilize, I'd lose my shirt because I sure as hell can't bill a client for three hours standing there staring at a GPS, doing nothing but waiting for it to warm up.
If I was an F-Class or Precision Rifle competitor, maybe I'd have a lot more patience.