Saturday was the DST change and we're facing a situation with osTicket that causes the Agent's lock to be expired as soon as they open the ticket to reply.
We've checked to make sure that the TZ detection is getting MST/Phoenix instead of MST/Denver and we've even tried changing the timezone on the server to PDT (since that is the same as AZ's all-year MST).
No luck in any case.
Everything else on the server is showing the proper date/time.
Our version is 1.10.5 running under CentOS 7.5.