Boundary timer event not triggering on timeout

Hi

I am facing issue with boundary timer event in my flowable workflow. I have set timer to 1 min PT1M, but timeout is not triggering. I have set asyncExecutorActivate=true in my configuration. Could you please help what can be the issue. Pasted workflow sample below.

Application Spring Boot
Flowable version 6.8.0

Property Set
flowable.asyncExecutorActivate true

<boundaryEvent id="timeout" attachedToRef="managerApproval" cancelActivity="true">
  <timerEventDefinition>
    <timeDuration>${expirationInDays}</timeDuration>
  </timerEventDefinition>
</boundaryEvent>