Getting ERR_CONNECTION_CLOSED on some runs

It is unclear to me why the connection is closed as they should all run.

Is there some “feature” that is blocking this?

https://github.com/DanielRuf/website-checks/commit/2b6dadc579a84ca1f0a291377ae64b7863510d35/checks?check_suite_id=273472470#step:5:8