Firefox browser not activating focus on URL open

[sagebind]

I am having an issue where it seems that triggering an open operation for a URL does not activate focus of an existing open Firefox window. This works on other desktop environments on the same system.

To reproduce:

1. Open a Firefox window.
2. Switch to a different workspace. (Not strictly necessary, but ensure the Firefox window is not currently in view.)
3. Open a terminal.
4. Run xdg-open "https://example.org"
5. The existing Firefox window will open the URL in a new tab, but will not automatically gain focus as expected.

This seems to be a global issue and not just xdg-open. For example, open any other application that presents clickable URLs to the user. Clicking those URLs in other applications will open a new tab in Firefox with the URL, but not activate focus of the Firefox window.

This seems like possibly some sort of Wayland window activation request issue, as a layperson with a very limited understanding of Wayland protocols.

I have validated that Firefox is running using Wayland and not X11.

System Information

• niri version: 25.11

• Distro: Nobara Linux 43

• GPU: Intel Iris Xe Graphics

• CPU: 12th Gen Intel(R) Core(TM) i7-12700H

[Sempyos]

Not a niri issue, add this debug flag:
https://yalter.github.io/niri/Configuration%3A-Debug-Options.html#honor-xdg-activation-with-invalid-serial