Not sure what could actually be causing it. But after a while into my campaign the two leading crew (skipper and boatswain) disappear and become non-interactive. Their portraits are there but I am unable to click on them or use them for anything

I should add that it happened after I completed the Enigma mission where it put an extra officer named Prien on deck. Once I got back to port I removed him. Then on the next patrol mission it screwed up my save game. Could even be a base game bug.

@Ivixor
Thanks for the report.
I don't think that related to this mod. If I understand you right the skipper and boatswain are disappearing from the boat and/or right corner portraits or otherwise becoming uninteractable during gameplay.
If it's not a problem on the crew screen itself then it's probably unrelated to this mod.

At worst I would expect that if something went wrong the officers would get an empty role, but would otherwise be unaffected.
I have seen the officer roles tab of the crew screen become unusable, but things have to go very wrong for that to happen and it's not something that happens during gameplay, it would be like that from the start.

Correct. It was a strange one as it happened after the enigma mission. Thanks for the response.