F-Droid clients apk cannot be installed in secondary user account

General

• Device OS and version: Tablet, Android 9.0 (but I had similar issues already earlier)
• Device model/manufacturer: Samsung SM-TM950
• F-Droid version (in the About screen): ? apk downloaded on 2019-07-12
• F-Droid privileged extension version (if installed): -

What did you do? (clear steps if possible)

• download the f-droid client from website on 2019-07-12
• try to install the apk (after enabling the permission for the downloading app to install apks)
• install fails

What did you expect to see?

F-droid install successful and working.

What did you see instead?

"installing app..." "App was not installed"

Additional Info

The same APK works on the primary account of the device. And when I install APKs directly they work also on the secondary. Today my workaround is to use G-Droid, which works.