Issue with new user account and on screen navigation buttons instead of capacitive ones

(Issue title)

Summary

I am using a phone with capacitive navigation buttons below the screen. /e/ offers in its settings to switch them off and use on-screen buttons instead. The on-screen option seems not to work correctly when adding a second user.

Steps to reproduce

Go to Settings/Users & Accounts/Users
Create a new user (a new account is created subsequently)
Long-Press On/Off-Button and select the new user.
The new user now has the same on-screen buttons being displayed.
Switch back to Admin. Now Admin does NOT have on-screen navigation buttons anymore. (THAT NOT AS IT SHOULD BE).
Restart the phone
Now Admin does have on-screen buttons.
Select new user: No on-screen buttons are being displayed here. (THAT NOT AS IT SHOULD BE).

Tested on Santoni with latest /e/ (Oreo from 20190920)

What is the current behavior?

Described above. Under certain conditions when switchen between Admin and a newly ceated user account the on-screen buttons are disappearing.

What is the expected correct behavior?

When on-screen buttons are being used on a phone (instead of capacitive ones) and a new user account is being created the same on-screen buttons should appear and when switchen back to the admin account the on-screen buttons should be displayed as they were initially.

Edited Sep 23, 2019 by Ralph Böhlke