Ctrl+. (Dot) makes "e" appear instead of showing suggestions in VSCode on Gnome

I'm using VSCode on Gnome (on XOrg on Arch). Since lately, the shortcut Ctrl+. stopped working, despite still being listed in the keyboard shortcuts and despite all extensions being disabled. Instead, an underlined e appears:

The character goes away when pressing enter twice or ESC once. When writing something and then pressing enter, the e goes away but the written text stays. When changing the window while the e is underlined, it becomes a regular e.

This seems to behave somewhat similarly to the compose key, which displays an underlined centered dot after being pressed.

I can't find any keyboard shortcuts for Ctrl+. in the Gnome settings.

What is this feature? What is it good for? And how can I restore the original behavior?

This is not related to VSCode, as the same thing happens in any text input field across all apps (both on Wayland and Xorg, Fedora).

The issue appeared on my pc when I upgraded to Gnome 42, and I still can't find a way to fix it (keyboard shortcuts don't have any entry for Ctrl+.).

Edit: Found this post about this issue. Their fix is to run ibus-setup and to disable the ibus shortcut.