Hover preview not working

[Rich.Allaire]

Hovering over profiles and presets changes the histogram but the live preview doesn't update till I click. It works in Lightroom and Lightroom Classic but not in ACR for some reason. Hardware acceleration is enabled.

Any insight is appreciated.

[TheDigitalDog]

First, try disabling GPU in the preferences (Preformance tab). Any better?
If not, recalibrate and build a new ICC display profile, the old one might be corrupted.
If you are using software/hardware for this task, be sure the software is set to build a matrix not LUT profile, Version 2 not Version 4 profile.
If turning OFF GPU works, it's a GPU bug and you need to contact the manufacturer or find out if there's an updated driver for it. 
Also see: https://helpx.adobe.com/photoshop/kb/acr-gpu-faq.html