Hello,
In workorder we have a look up column "Service Territory" coming from service accounts, on few of the work orders we found that system has removed the originally assigned service territory value.
Can be seen in below audit history - User one assigned territory "7-East" and after some days System removed that value.
When we click on Event > Update we get below details.

Above changes have happened to couple of work order records. System status for few workorder is "Completed" and for few of them is "Unscheduled" and few of them is "Scheduled"
Can you share the reason why system updated the field/column value.
Looking forward for your inputs.
Thank you in advance.