ACR gets very slow several hours after reboot

I have 2 computers with similar, but not exact, configurations. I have no problems on one computer, but the other computer (the one I use most) gets VERY slow.

The computer in quesion has an Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz 3.60 GHz with 64gb ram and a NVIDIA GEFORCE RTX 2060 Super video card. This is a Windows computer, and I've had this problem for well over a year now, spanning Windows 10 and Windows 11.

After a reboot, ACR is great - images load quickly (very large RAW files load in about 4 seconds) and editing is smooth. But, after a few hours, even if ACR isn't used, it gets very slow. It can take 30 seconds to load one image, and the sliders are all very sluggish - after making a change, it can take up to 10 seconds for the change to take effect. 

At one point I had "Acronis True Image" loaded, but was removed many months ago, as I know there have been issues with that software. 

I've tried loading/unloading various programs, but nothing seems to make a difference.

Has anyone else had this issue, and if so, any solution??

Thanks,

Bert