Hot side temps

So yesterday I changed Socks bedding and everything and before I was using repti-bark and I switched to COCO husk for humidity reasons, and now I can not get the hot side temperatures up to 92, they are hoovering around 86-88. The UTH is at full power and controlled by a thermostat and I am still not hitting the right temps. Its a very old UTH and it doesnt stick very well to the bottom of the tank. Should I upgrade to a new one or could it just be because of it the bedding being moist. And BTW the bedding is only like 1/4 thck. you can see the glass its so thin and I cant get the temps up.

You can have a thinner layer. It would be warmer. And 88 is ok for a hot side too.
But you should probably replace that UTH heater anyway since it's old. It can be a potential fire hazard if it malfunctioned.

86 to 88 is the correct ambient temperature, 90-92 is the temperature you're looking for directly on the UTH inside the tub.

I would suggest getting a new uth if it's as old as you make it sound, house fires suck...