It looks like this bug was introduced in AppStudio 9.1.6, when we updated the wxPython library. It seems to be OK in 9.1.5.
You can download that here:
https://download.appstudio.dev.us-east-1.linodeobjects.com/AppStudio-v9.1.5.1.dmg
We’ll continue to work on a solution for the latest version.