A360: Timer not resuming

Hi all, 

I've been working on an e-learning module that includes a timer-based hotspot question. This template has worked typically in the past but in this current module, the timer doesn't resume after closing the top layer (see the attached module for a better understanding). 

The error is a little inconsistent. Sometimes I can make it through 2 hotspots before the timer pauses, other times I can't even get through 1. None of the triggers has changed in the transition of the question from one module to another so I'm totally baffled by why it won't work correctly in this case. 

Thanks in advance for any help at all,

Josh