phtn.app keeps stuck on the loading screen (Falkon web browser)

Just a few moments ago learned about phtn.app, as I was using photon.lemmy.world. I'm trying to use it with KDE's Falkon web browser, my daily web browser in desktop, which is based on chromium (though as far as I know it's not cutting edge chromium).

photon.lemmy.world works just fine, but I don't get to pick spanish from the available languages - while in phtn.app is there (I used Firefox's web browser to check it and learn there's quite a few differences between phtn.app and photon.lemmy.world).

The thing is that phtn.app stucks on the loading screen (the circle spinner) with Falkon. Not sure if it's Falkon being funky or there's something that could be done on phtn.app. All I can see in the web inspector is the following:

Not wanting to pull Firefox/Chrome/whatever and all their dependencies just for this, so I'd like to know if this can be addressed in phtn.app's side.