Ah, I found a workaround: Firefox on Android has a "[x] See the computer version" option which allows the merge!?
Well that's annoying.
I would like to see this fixed and it's on my workflow todo list, but obviously that list is not short so I don't know when I will get to it (especially since at some point I will need to take a workflow break and actually write code and review PRs again ;) .
Codecov actually only runs under Travis, so it's only testing on Linux.
I personally disagree as code that isn't tested isn't checked that at least some semblance of backwards-compatibility is being kept. Now I'm not advocating we must have explicit tests for every line or code, but I think we should somehow exercise as much code as possible.