Under GNOME Zathura maps my keys differently depending on the mode

I use zathura and have a Swiss German keyboard layout on two system. One of them uses Sway and the other GNOME. The one with Sway works just fine. On GNOME, however, the following happens:

In order to get into command mode : or search mode /, I need to press the keys where those characters would be on a US layout. Once I am in any input mode, however, the mapping works as expected (Swiss German) with no issues.

Unsure whether this is a Zathura or GNOME bug, or both, but I would appreciate any advice. Thanks :)