Took me a while to figure out that I needed to shake the synthetic brush to get rid of excess moisture after wetting it, else end up with a very thin lather that is susceptible to flying all over the place.One adjustment it took me a while to make was to factor for how differently a synth holds water compared to a natural fiber brush. Your badger is soaking up and retaining water compared to your your synth which just keeps water on the surface of the fiber.
For me, this means I need to add less water and add it later in the lathering process than when I'm using my synth brushes.