[GNC] New accounts don't show up in GC 5.8 under Flathub

[rsbrux]

When I create a new account in GC (v5.8 running in Flathub under Ubuntu 
Studio 22.04 LTS), it doesn't show up in the account tree.

Clicking "View - Refresh" does not help.  The ony way I have found to 
get the new account to show up is to use "Edit - Find Account".

The new account then shows up in the search results, but with a 
checkmark in the column "Not Used".

When I double-click on the entry in the search results list,  the new 
account appears in the account tree.