Less is more. Simplify. Go back to the yard and firm up OB. Proof with heavy distractions. Then de-chase with live flyers while under command. Then link it together with shot flyers. The dog does not get the retrieve unless it does everything right. Set the bar where you want it. Then be consistent. Once a clear line of communication is established and communication is crystal clear, using birds as motivation is powerful. It will close the deal with a positive influence on style and pay dividends with brace work.
This is what it should look like when the dog has the mark. If OB in the yard is not good enough to sit motionless without distraction, there is no point in asking it of the dog in the presence of birds.
This is putting it together on pointed birds. The dog is already steady to shot and fall and has been de-chased. It has a bird pointed. I have walked up and snapped a lead to a pinch collar. A helper is going to flush the bird. If the dog breaks it will correct itself. If it remains steady, the helper will shoot the bird. Again if it breaks it will correct itself. If it remains steady, it is released to retrieve. Building a strong foundation with baby steps and drawing on the dogs love of birds is the path.
These pics are my Pudelpointer which are wired very similar to your Vizsla. There is more than one way to get where you want to go but that is the readers digest version of how I go at it. Good luck with your steadiness training.