Hey there! I recently noticed that the S Pen on my Tab S9 FE
"lags". It keeps writing for a few milliseconds despite me lifting it from the display, which creates strange effects This mostly occurs in the case of me putting more pressure on the pen while writing, especially if I'm writing fast. It can be seen in the video attached. I encircled the actual effect in red several times so that You can see.
Are you using a cover with a magnetic closure or other magnetic parts? If so, remove the cover and check whether the problem persists. With the S-Pen, this problem occurs when there are magnetic parts in the vicinity.✌️