SPen TabS6

[HerveN]

Ever since Android 10 was installed, my S Pen is behaving funny. It starts doing things on the screen even before I touch it, things like moving the text up and down instead of waiting for me to touch the screen and drag the text up and down. And when I finally touch the screen, it does not behave like a touch. None of this was happening when it was running the version it came with, Android 9. I tried to cancel everything on the S Pen setting page and this is still happening. Are others having this problem?

[BandOfBrothers]

Look at clearing the system files cache @HerveN 

Clear your phone's System Cache Files by turning your phone Off and then from a set series of button presses go into the phone's System Files and clear the cache. No information is lost this way. 

Also as a last resort back up and factory reset.