Could this be a bug caused by the fact that I have two screens (Moto Razr+)?

Doubt it. This happens a lot for me too on a boring single-screen S23.

I assumed it was crappy devs not testing on FF anymore & have lived with it (since it’s a pain to debug css/js problems on mobile).

Next time I see it happening I’ll reproduce on desktop FF with responsive emulation & report the bug.

Totally OK way of doing it. You basically manually implemented the protocol APIPA uses to allocate 169.254 addresses.

In addition to the excellent https://sci-hub.se suggestion…

I can find the paper for free 90% of the time by googling the authors and visiting their personal page on their university’s website.