Hi everyone, thank you all for your feedback on this request.
I'm happy to announce that in Bitbucket Data Center 7.19 we have shipped a check that logs a message in the mirror logs if the clocks from the upstream server and the mirror drift too much. The log message reads "Upstream and mirror clocks are out of sync by XXXs, check the system clocks on the upstream and mirror nodes. This can sometimes cause JWT authentication to fail"
You can read more about Bitbucket DC 7.19 in release notes.
Senior Software Engineer