[GNC] sub-windows always staying above main window

[Amish]

Hello

This is a bit of inconvenience introduced in version 3.0

Earlier when I open sub-windows like "Find transaction", "Due invoices 
reminder", "Due bills reminder", "Find invoice" etc., a small window 
would open.

Earlier after opening those windows I could press "Alt-Tab" and switch 
back to Main Gnucash window.

Now I can still Alt-tab but that small window will remain on top of the 
Main window covering major part of Main window. Every time I am forced 
to minimize small window to see Full contents of Main window.

Can we make it like older version? Where small windows simply go behind 
Main window on Alt-tab.

Thank you

PS: Using Linux - Arch Linux. Gnucash v 3.0.

Amish.