they recommend swapping UV bulbs every 6 months, so it might be starting to get fucky.
Man I wish solarmeter 6.5s werent so fucking expensive, I just cant justify the price for something I'd end up using like 3 times a year at most. My sister's got an RES, maybe I can convince her to go halfsies on one with me and we just swap it back and forth as needed.
Did your turt have a period where he behaved normally in the new tub, or has he just not gotten out of his "new place I may be in danger" phase? Maybe toss some extra hides under the water so he doesnt feel as exposed in the new digs?