Hello, My name is ***** ***** I have been a Vet tech for 30+ years with special interest in reptiles and reptile rescue.
Can you tell me about the set up?
Temps in enclosure?
The firs problem I see is the calcium sand it is deadly. When ingested it will eventually harden in the intestinal tract and cause a blockage. Geckos taste their surroundings and in doing this get the sand in their mouths. No loose substrate is safe. I suggest cage carpet, tile or paper only. As far as the behavior, They are active at night which is very normal. In activity at night usually mean something in the habitat was wrong and now since the move they are active again. As far as the red bulb I would not use that since they are know to case thermal burns. Geckos like heat from underneath. Generally an under the tank heater on a thermostat is used. You can use the black light bulb which is much safer in you use a bulb from above.
Right now with what you have said the only thing that may be off if the slower appetite which we do see in during breeding season. At this point in time I would continue to monitor them. There is nothing specific that I could pinpoint that seem wrong. You could have them see a Herp Vet and I can give you a link for some if you tell me where in the UK. Other than the calci sand all seems good.
It is called glass dancing and usually when they are active and happy this is done. We do recommend a moist hide to aid with shedding and keep it on the warm side of the tank, but it should not cause a problem in the tank. If I have addressed your concerns, please take a moment to rate my service 5 stars.