My ship only shows crew currently on your own vessel. On a smaller ship, or between contracts, there may genuinely be nobody new right now.
Everywhere shows verified crew across the fleet. If you have swiped through everyone available, Discover will look empty until new profiles join or become eligible again.
Running out of people is not a bug. It is more common the smaller your ship’s crew is, or if you are one of the first people on Seacove from your line.
If Discover is empty and you believe it should not be (for example, you know other Seacove users on your ship), check that your ship and status are set correctly in your profile, since a mismatched ship will not show the right people.