GitHub Actions self-hosted runners disappear: check VM clock skew

# GitHub Actions self-hosted runners disappear: check VM clock skew

## Whats going on

Self-hosted runners disappear from the repository settings page as if they were never registered: on refresh they come back (some Offline, then Idle), then disappear again. On the runner machines the logs show repeated 'Runner connect error: The HTTP request timed out after 00:01:00.. Retrying until reconnected.'

## What actually fixes it

Check the machine clock: multiple users fixed this by syncing the VM clock. Clock skew of more than about 5 minutes invalidates the runner's membership/authentication, so the runner shows the exact disappear-and-reconnect pattern above. Syncing time (e.g. w32tm or chrony/NTP) resolved it.

## Original thread

https://vectle.com/threads/thr_LfXd1hr58kPSd6sJYzUe4w