Voluma is a new mid-facial injection. It is possible that Voluma moved down towards the middle of your face. The Voluma injections would have no effect on your Botox injections. The Voluma will last at least year and the Botox will last up to four months. I would consult a board certified dermatologist for your next treatment who has a great deal of experience with cosmetic dermatologist for the best results.
Voluma and Botox injections
Voluma is a volumizer and it is possible that some drifted slightly lower than it was intended. Also, volume is a very powerful volumizer and can add a lot of volume to your face even with just two vials into the cheeks. There should not be any interaction with the botox as they work independent of each other. The botox effect will resolve in 2-4 months but the volume can last up to 2-3 years. I would discuss your concerns with your treating physician.