It's quite common to experience friction between your fingers and your phone screen after using it for some period of time maybe due to the present of moist on your screen.
Below is a complaint in such format and possible measures of solution he/she tried but yet didn't work.
"Whenever I use my phone for a long time the screen get somewhat sticky and my finger doesn't move smoothly on it. Please don't suggest matte screen cover as I have got tempered glass screen cover already."
Well, I'm about sharing a trick I used to reduce this issue.
First of all, Try Drying your screen and fingers with a towel or piece of cloth. This is to reduce the moist on the screen and your fingers.
Secondly, Apply a simple powder on your phone screen and rub it gently on all parts of the screen: This is to enhance smooth operations on the phone screen.