There is a current known issue with the 4.0 release of the SRA with ActiveDR when the replication link is paused between the source and target pod.
The Synchronize Storage step will appear to hang at 100%:
Go to the either FlashArray in the ActiveDR pod pair, and navigate to the pod and in the Pod Replica Links box click the vertical ellipsis and choose Resume:
Confirm the resume operation:
The recovery will then complete once synchronized.