Thank you for checking. I just installed a completely fresh and clean openbeta install, did a cleanup and repair straight afterwards. No mod's installed, completely fresh. And the first run of mission 4 gives me the same kind of results as before. Before Weed could hook onto CAT4 but would stay there forever. Now Psycho hooks on CAT3 and stays there forever.
Every time I run this mission I get a variation this bug. I don't know what else to say. tried at least 20 times by now, never had a time I couldn't reproduce this bug.
The campaign is awesome, it's my 3th time replaying the campaign. Hope one of you guys can figure it out