No, I'm not a doctor. I didn't realize you'd spoken to your doctor about it. Yes, it is a classic dystonic drug reaction. Assuming, of course, that the drug is the cause. You'd only demonstrate that, IMHO, but doing the discontinuation and resumption of the drug. That's called a dechallenge/rechallenge trial. It reduces the doubt about coincidence.

Make sure you tell your doctor if the problem gets worse, or you get other signs of involuntary muscle contraction or movements.

Lar