It's definitely the same problem as before - captured captains are not being properly cleared, are stored in the background, and eventually there are so many of them that no new captain can be created for you to capture or fight. But this tended to happen if you hired or executed the captain. Like you, I either ransom them or release them for reputation, depending on how much ransom is being offered, and I never saw the problem in any of my games even before I fixed it for hiring and executing.
The fix is the same. Look at this post:
Fixed - Marie Celeste
Download the file "console.c" into your "PROGRAM" folder. Load your savegame, press F12, and you should see a list of ex-captains being cleared. You can then board the ship and meet the captain:
View attachment 42195
(I have ammunition for pistols enabled, you apparently don't, which is why there's a row of four empty shots over your status icon. That is nothing to do with captains.)
But there's something else odd about your game:
View attachment 42196
The questbook shows that you are playing "Tales of a Sea Hawk", which is set in 1750. So why is the date showing 1693?