This is fantastic! Thank you for providing yet another modified file to debug the timestamp.
I contacted our university's Blackboard people. I hope we will hear from them soon. Collecting the info with your modified file certainly helps to figure out the issue.
Our Webwork is running NTP:
Local time: Mon 2021-02-15 13:38:58 EST
Universal time: Mon 2021-02-15 18:38:58 UTC
RTC time: Mon 2021-02-15 18:38:58
Time zone: America/New_York (EST, -0500)
System clock synchronized: yes
NTP service: active
RTC in local TZ: noI will keep you posted of what is going on.
Thank you gain.