OJS2.4.8.2 and OJS2.4.8.5 Review automated email reminders enabled, but not dispatching

Background:
Current version OJS 2.4.8.5, recently upgraded and switched to PHP7.3. However, our record shows automatic reminders last_run value are 2018-02-01 which matches the 2.4.8.2 upgrade date.

Request:
Any advice on why this could have occurred and how to fix this?
auto-reminder%20failure

Best.