Professor palin not unlocked?

Have you tried turning it off and back on again?

Seriously, a lot of things like this seem to require logging out and back in to trigger them. I'm pretty sure I had to do this at certain points in unlocking Farseer and Martuuk. More recently, I had to do it to activate my Sol Permit - despite having received the message saying that I had it, it wouldn't work until a re-log.

As long as the right panel statistics show max distance from start as over 5000 LY, you should be fine. Seems to take a few jumps after that for the invite to show up.

Also note: you don’t have to survive; you can go 5000LY from start, self-destruct and still get the invite.