I have noticed this bug as well. I have 1882 crew, and I should need 188 sergeants, but the game is demanding I have 267 sergeants.
I'm also have an issue with the morale loss from lack of officers. Between the time it takes to find them, hire them, and then have them train up, my morale takes quite a hit.
There seems to be another part to this bug. I had a bunch of extra untrained crewmen leftover from when I was scrambling to fill my mechanics before the economy patch, and I no longer need so many, so I thought I would dismiss some to lower my officers needs.
Despite dismissing over 100 crewmen, my sergeants requirement did not change at all.
On further inspection, I'm not sure if this is a new problem, or an old one. My first real ship hasn't needed more officers in a long time, but I noticed it also has too many.