I have kind of a similar problem.
I just bought an OM-4 Ti on the bay and it's a very nice camera.
Out of the box it seemed to be working just fine, I replaced the seals and loaded a roll, everything was working great until the camera started behaving strange.
Sometimes I had to wind it twice or even more to be able to depress the shutter button and fire the shutter.
After a while a noticed I could get around the problem by making sure the wind lever really went all the way on the first wind.
So I loaded the next roll and took two or three shots and then it all just got stuck.
The wind lever won’t move because the shutter is already cocked and the shutter button won’t go anywhere.
I have tried fresh batteries, the mechanical speeds, taking batteries out over night, I even took off the bottom plate and tried to trip the shutter from there.
Nothing helped a bit 🙁
Any ideas?