Feels like something moving behind uvula and tonsils in far back of soft palate.. what could it be? doctor says uvultis but it feels like s/t moving..

Sinus or Allergy: It could be sinusitis or allergies. What you feel could be mucus drainage. Have you tried an over-the-counter (otc) decongestant? If this doesn't work, then you may need to go back to the doctor to see what the issue is causing your symptoms.

Post nasal drip: It can be post nasal drip if you have nasal congestion and sinus congestion.