I have seen this episode a number of times. I believe while it is mentioned that the Typhon Expanse (as being explored in the episode) is largely unexplored, there does not appear to be any issue restricting communication with the Federation or Starfleet.
As the Enterprise continues to loop, the crew slowly becomes aware that they may have been stuck in this loop for an indeterminate amount of time.
I believe Geordi even says something to the extent of "Days, Weeks, Months... who knows?"
However, it isn't until the near-collision with the Bozeman at the end - that Picard finally orders computer clock synchronization with that of a nearby Starfleet time beacon (or something to that extent) to find out that they had been stuck for about 17 days.
Is there an in-world explanation as to why they would have not either tried the synchronization earlier, or even communicated with Starfleet for guidance on the situation? Presumably, someone at Starfleet would have noticed they haven't heard from the Enterprise for 16 to 17 days.