Firefox not respecting wayland system theme

Hello all, I have an issue with Firefox 122.0, in which the theme looks like Adwaita, and not like KDE Breeze dark. Remarkably, not only the window style changes with respect to the default, but also the mouse changes to a massive version of Adwaita. In the image attached you can compare both chromium, which doesn't have this issue: notice the window decoration (sadly the cursor can't be included as a part of the screenshot, but it's definitely not KDE Breeze dark's). What causes this behavior? Is it internal to Firefox, or is it rather a user option that I did not correctly set? Thank you in advance.