Problem with Prontor svs

I've opened the lens on a Voigtländer Vito B with a Prontor SVS shutter.

After removing the speed cam the film advanced and the shutter cocked and fired correctly, but then started acting like on this video.

Before the video starts, the shutter has fired. At the beginning of the video, the winding lever can't be pulled. After pushing the shutter release, I can wind the film. The winding ends with the shutter firing. Then the same sequence repeats.

Can anyone see what is going wrong here?

Here is the same video on Vimeo if you prefer.

That problem normally means that the latch holding the shutter cocked is not latching.

Try Zippo in each sub assembly until fault clears...