Scrolling slow on MacOS High Sierra and Mojave

Steps I took that resulted in the problem:

I’ve had 0.9.3 installed on High Sierra for years, I just thought it was a Mac thing. Now with 0.9.6 on Mojave and it’s the same. Painfully slow.

What I expected should have happened instead:

Same as on a linux install, scrolling follows the mouse

My version of Fritzing and my operating system:

Good: 0.9.3 (Debian Jessie) and 0.9.6 (Debian Buster)
Bad: 0.9.3 (OSX High Sierra), 0.9.6 (MacOS Mojave)

Please also attach any files that help explaining this problem

Not a file but a question - can I change the drawing routines on MacOS? Maybe it’s an issue with QT5.