05-21-2022, 08:20 PM
The one that came pre-loaded on my (regular) PinePhone recently was Manjaro with Plasma Mobile (so, what allworlds said) and I only saw Angelfish there. The specs for the Pro say "OS: Manjaro with Plasma Mobile (pre-Beta build)" so you probably have something similar on yours. But, Firefox does seem to run fine on the Manjaro + Phosh install I'm trying from https://xnux.eu/p-boot-demo/. (I've been finding that bootable image really helpful for trying out a bunch of OSs and interfaces one after the other.)