Sluggish responsiveness on iMac 5k 2017, macOS 110.5.7

Hello, forgive me if this has been addressed anywhere, but I could not find it.

I am using an iMac 5k 2017, macOS Catalina 10.15.7, and Audacity 2.4.2.

I also use the same Audacity version on an older MacBook Pro, with macOS Mojave 10.14.*

My issue is that on the iMac running Catalina, the usage is choppy, sluggish and irritating to navigate. In terms of audio, it runs smoothly, but visually it responds in a very choppy fashion. This makes selection and scrolling/scrubbing very difficult. The behavior began when macOS updated from Mojave to Catalina on this particular machine. Using Audacity on the iMac 5k was as smooth as usual prior to the OS update.

On Mojave (on the MacBook Pro), the issue is non-existent with the same Audacity version.

Anyone have a clue as to what could be causing this? Thank you in advance!

Right-click on the Audacity application icon and select Get Info. In the Get Info window, check “Open in Low Resolution”. Does that fix the problem?
– Bill

YES YES YES! Significantly! I’ve been searching high and low for this solution, because I assumed the high resolution screen was causing the rendering sluggishness. Thanks so much Bill.