Lately, on occasion, I'll be typing and will move the cursor to a new line. I'll just type a sentence or two, look up, and the line is blank. Cursor is absent for a few seconds, then appears and all is fine. (due to disability, I can no longer type 80 wpm without looking at the keyboard. I have to type with 1 finger, yes on keyboard). Why is my cursor seemingly freezing when it feels like it?