Multiple users: the second one cannot install any app

/e/ version:
Device model: samsung galaxy tab S2 SM-T813
When it started to occur: from a fresh flash
Reproducible with the last /e/ version:
Reproducible with LineageOS:

Summary

The device is unusable by the other user
The bug is the source of a data loss or a big waste of time
The bug concerns a third party app
The bug concerns security
The bug concerns privacy

The problem

Steps to reproduce

When the second user try to install something from Apps, the system hangs on "installing" apparently forever. The rest is still fully usable.

If the second user try to install another app, i.e. fdroid.apk downloaded from the net, he/her is warned about the risks, he/her accepts them, the app installation starts, but eventually results in. "App not installed"

What is the current behavior?

Described above

What is the expected correct behavior?

The second user must be able to install his/her own apps

Technical informations

Relevant logs (adb logcat)

Relevant screenshots

Solutions

Workaround None, to my limited knowledge

Possible fixes