Oh, the bane of my existence! About every day, I accidentally enter a type of editing mode that nobody has ever used in practical word processing: The overwrite mode. NOBODY freaking likes it, I’m sure of it. It is a curse from the New Bit Demons.
To clear it:
Press the Insert-button. It maybe behind another button like fn-button (function) or sift-button.
That should get things back to a blessed state.
You could be searching for a solution to the cursor problem, maybe text being overwritten, cursor becoming unusable… How to fix a cursor that no longer works… Just to guess what you might be searching to find a fix to a cursor acting funny.