Was this a migration issue, a time change issue or a combination of both?

Had an interesting fluke we noticed after our system migration from a Power
9 to a Power 10. Exec team is currently on a retreat. A salesperson calls
just noticing that he hasn't received his daily sales report since then.
So we do a WRKJOBSCDE and notice that it's not on hold, etc. Job
description, job queue, etc are used for numerous other jobs so that's not
it. Then we noticed that the next submit date was for 10 days ago (day
migration completed). Weird. So I ran this SQL:
SELECT *
FROM QSYS2.SCHEDULED_JOB_INFO
where NEXT_SUBMISSION_DATE < current date
;
and that was the only one in this condition.

Prior to that it was running fat, dumb and happy as evidenced by this:
select *
FROM TABLE(QSYS2.HISTORY_LOG_INFO(current timestamp - 30 days, CURRENT
TIMESTAMP)) A
where A.MESSAGE_TEXT like '%ERPGLES1%' or A.MESSAGE_SECOND_LEVEL_TEXT like
'%ERPGLES1%';

But, then we noticed it was 2am sharp that it was supposed to submit. The
system was in restricted state as it was being saved/restored from the
Power 9 to the Power 10.
And, (drum roll please), there was no 2am on 3/12 due to the time change.
So putting your system in restricted state to prevent DST anomalies is just
a shot to the foot.
That system migration does require you manually set your time as you are
doing manual IPLs and get prompted for the system date and time.
To fix the job schedule entry so that it would start running:
1 - holding and releasing it did nothing
2 - Putting a 2 on it to change it and entering the screens did change the
next submit date.

In case it's significant, RCYACN(*SBMRLS)