Can't end patrol bug SH4 FOTSRU
 

As the title describes, upon returning from one of my more successful patrols to Brisbane (my homeport), the End Patrol button is greyed out.
I have checked and there are no radio messages indicating my base has changed, and Brisbane still has the slanted anchor.
I've tried loading from the autosave upon returning from the patrol before this, doing the patrol again and returning and I'm coming across the same issue.
In case this info is relevant: date is April 1943, Balao Class boat.
Also, as this is my first post I thought I'd say hi everyone! glad to have become a member of this community.

more than likely, your difficulty is due to your acceptance of the Balao upgrade early in 1943.
Balao's should be home ported at Pearl until later in the war AND are not supposed to be available until later in 1943.
so....because you were so successful as a sub driver, you stumbled onto a SH4 bug which awards you a boat before-its-proper-time.
there is no fix.
your only hope of continuing your career is to reload the mission prior to your upgrade, finish that mission, and then refuse the upgrade.
if you don't need/want to continue that career, then start a new career mid-to-late 1943 and start it at Pearl and you can get a Balao from the start.

good luck, Herr Kaleun!
:Kaleun_Salute:

Ahh thank you for your information. I tried using that idea by sitting outside brisbane until when it supposedly is meant to be offered there (according to information I found on the sh4 fandom page). However that failed too.
Unfortunately, once I return from a patrol I delete the various saves I made that patrol, and the autosave from port entry us from after I accepted the upgrade, leaving me with no alternative but to give up on a career I've put 75 hours into:(* if anyone else has any other suggestions please do let me know because I want to avoid having to do this at all costs.