GitHub PR not being updated with final coverage data

@tom This happens for every single PR, and has been happening for a month at least.
Sometimes the comment is missing completely, but most of the time it just doesn’t update it.
See Use a constant to load adler-32 initial hash value. by nmoinvaz · Pull Request #604 · zlib-ng/zlib-ng · GitHub for the most recent example of missing completely.

This used to happen before too (we had lots of problems before, making codecov completely useless), but everything was pretty much fixed in early March (most comment reports were complete, just a few were missing a couple of the CI runs).
Ref: Codecov server 500 error and endless "processing" - #8 by Dead2
But after 2-4 weeks, the comment problem came back again in full force.