Branches from PRs may be empty and it's unclear why

[Byron]

Here is the view when it's entirely empty.

It's notable that we don't know by what measure we list PRs.

• are we missing remote tracking branches?
• what's the remote it would ask for PRs?
• (was an error squelched by any chance?)

Can we make it clearer as to why the list is empty? Where there no PRs at all to show as per GitHub? Is it possible to give instructions on how to see PR branches?

PS: This is how it looks like when there are branches:

[Byron]

CC @PavelLaptev, it will probably need more time to figure what to do here, but I will give it an AI-shot anyway.