iMac 27" (Late 2015) R9 M390 2GB Video issues after updating to Mojave

[geo88]

I'm getting occasional random video glitches after updating this machine from El Capitan to the latest Mojave 10.4.6. Sometimes it really gets bad. Everything went smooth with the update. I used a High Sierra install media I had on a flash drive, and then updated to Mojave via the App Store. Everything was fine before the update. Does anyone have experience with this?

 

[geo88]

I see that quite a few Adobe Creative Suite users have reported this. Disabling the GPU acceleration setting within InDesign and Illustrator is the temporary fix. Apparently updating to Catalina resolves the issue, but that is not an option for me. Still depending on some 32-bit software.

I wonder if there is a firmware update included with the Catalina installer. Is it possible installing only the firmware update could fix the problem?