Extra unnecessary Gnome keyboard bindings are created

[jojhelfer]

Describe the bug
Every time I open Dropdown terminal X, the keyboard shortcuts <Alt><Shift>4 and <Alt><Shift>5 (and presumably <Alt><Shift>n for any number key n) mysteriously become bound so that I cannot use them in other programs. I can free these shortcuts by binding them to something else in Gnome Settings->Keyboard Shortcuts and then unbinding them, but then as soon as I open Dropdown terminal X, they again become unavailable.

To Reproduce
Steps to reproduce the behavior:

1. Open and close (i.e., toggle twice) Dropdown terminal X
2. Open emacs
3. Press <Alt><Shift>5, which normally runs query-replace and queries for a search term, and observe that this does not work.
4. Open Gnome settings->Keyboard Shortcuts
5. Choose a disabled action (like "Eject") and bind it to the keyboard shortcut <Alt><Shift>5 (which will be displayed a "Shift+Alt+%").
6. Unbind the just bound keyboard shortcut (by clicking on the little "x" icon next to it).
7. Return to emacs and try <Alt><Shift>5 again, and observe that now it works.
8. Repeat steps 1-3.

Desktop (please complete the following information):

• Distro: Ubuntu 20.04.1 LTS
• Gnome-version 3.38.8
• Extension-version 17 (I think -- that is what it says in ~/.local/share/gnome-shell/extensions/[email protected]/metadata.json under version)
• Xorg or wayland? Xorg