As far as the Scouting missions ceasing to be generated are concerned, I ran the game on two separate occasions. The first time, they showed up often enough. The second time, they maybe started showing up again after choosing “Reject”? I’m inclined to believe it’s a weird case of RNG.
On the other note, you can review mission details with the “Recall Current Mission” command, accessible from the Explore->Mission Computer menu on planets.
There isn’t a good spoiler system on this platform, so I dare not speak too much more on this matter. However, if you’re on the mission I think you’re on, there should be a jump-gate in the vicinity of Remata in Nav 14 that you can access.