Comment 4 for bug 1754833

That's interesting.

If you close gnome settings, open it again, does it consistently say that the default browser is chromium? What are the other options in the dropdown? Can you confirm that firefox is not installed by sharing the output of the following command:

    apt policy firefox

It looks like it might be an issue with budgie's default settings that default to firefox (the ubuntu default) instead of chromium.