[#3517][7.50] Manager disappeared and I cannot place a new one

[alexearth4]

Savegame link: https://www.dropbox.com/scl/fi/qucjl4ko ... jkd3d&dl=0

No mods (vanilla), fresh start with 7.50

As seen in the personal log book, I placed my manager Ismail Sheppard on my e-cell production in Venus (I flew there, landed, and then told him to work there while landed). Shortly after, he just disappeared, he isn't listed in the station's Crew menu, he doesn't exist in the Personnel Management screen in Player Information, however the option to place a new manager there is greyed out and says that I cannot place anyone else there either, essentially making the station bricked.

EDIT: After restarting the game I can put in a new manager, but the old one is still gone together with the seminars I gave him.