yes, that's when it happens to me too, always after i eat or drink anything, i irrigate my sinuses with a navage, which is like a netti pot thing. if i don't do this then the phlegm will build in my sinuses...it really gets thick if it builds.. at the end of this month it will be 3 years for me from covid...i have a lot of other symptoms but this one is the one i hate most because it is always there.....hang in there..