Submitted issue to Apple as FB13098566.

Thanks for the response, really appreciate it. I understand the OS deciding when the operations should occur but in my experience once some time has passed before connectivity is restored the operations are never completed, until the app is in the foreground again. For users it's confusing as they're expecting the activity they recorded to be on their iPhone when they open it so asking them to go back and open the app again on the watch to trigger the transfer isn't very convenient.