On Sat, 15 May 2021 10:53:00 +0100, John Hall
wrote:

snip

Maybe the mouse is slipping on the pad? You could try cleaning the mat
and the underside of the mouse, as grease tends to build up. You could
even try dispensing with a mat, if the top of your desk isn't too shiny.

I once bought a 'proper'(?) optical mouse mat and the Apple mouse
wouldn't work on it at all and my Logitech optical mouse was far less
accurate on that than on my leg! ;-(

Cheers, T i m