A HT with a timer attached to cancel it, is correctly disabled if HT is completed.

At this point HT is the last save point

if next task launches an error, process is rolled back to HT (to state "In Progress")

But timer is not rescheduled. It is expected that timer is reenabled (with same trigger datetime)

timer is not entirely ignored, as check the SVG diagram status from process instance, reschedule the timer launching it if expired.

Provided a reproducer where timer expires in 2 min.

If HT is completed before those 2 min, timer is cancelled. but as next script task throws an error, process rolls back to HT, but timer is not rescheduled, until some operation like check the svg diagram for process instance

/server/containers/

/images/processes/instances/

timer is rescheduled (and if those 2 min had passed, that branch will just run at that moment)