You are looking at the CPU not the GPU 

This is the GPU with Chitubox open but not doing any work just sitting with a model on the platfrom (30-40%). 

The GPU with out Chitubox open. (0% CPU)

I can confirm this behaviour in 1.8.1 with a nvidia Geforce RTX 2070

It was not that way in earlier versions:

Doing nothing in Chitubox makes the GPU run damn hot when it's open. I once forgot to close it and i almost burned myself when touching the keyboard of my notebook on returning. That can cause serious hardware problems if unchecked.

It does go down to normal when minimized for some reason, but being open (even in the background) = almost unusable after a while

Since the version 1.8.1, I face to the same issue:

PC Asus VivoBook

Processor: Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz   2.59 GHz

RAM       16,0 Go

SSD                512 Gbytes

That appears when Chitubox windows id in full size and also in intermediate size window: the GPU rate rise up to 95%

I found a "temporary solution":

when you do not need to work on the model, reduce the chitubox window to the taskbar, then the GPU drop to 0% and the cooling goes down to quiet status after some seconds.

This problem has been resolved and will be updated in the next version

Any chance of posting a beta with the gpu fix. Im running a 8 core intel i7 with a RTX 2060 and this program is running really slowly on my machine and using about 80% of the GPU while its doing nothing. 

The same here. When doing nothing one cpu core is permanent at 100% and the gpu ( rtx 3060 Ti) is at 70%. Thats awfull. plese fix it

Same problem with version 1.8.1 and 1.9. (Geforce RTX 2060).
Program works very slow on GUI. Every mouse click take 4, 5 seconds to execute.
Slicing works normal.