i.e. here

It generates a link like this:

https://app.codecov.io/gh/tidyverse/tidyr?branch=main

but if you go to that, it will still show master. It does not seem to know how to handle ?branch=main and just ignores it, and then shows what it thinks is the default branch, which is master unless you've changed it in the codecov settings.

It seems like this might be a more correct link?

https://app.codecov.io/gh/tidyverse/tidyr/tree/main

That shows main for me