In some cases the schedule is suspended may not resume if the event has times in multiple of 10's.
E.g.
EVERY 10 MINUTES
Release : 12.1
Component : CA WORKLOAD AUTOMATION DE (DSERIES)
Some older Timezones affect the event schedules.
If the DE server is using Brazil Timezone, then update the java time zone.
The tzdb.dat should have correct "America/Sao_Paulo" time zone.