MacOS – Cursor changes position in input line after I highlight some text to overwrite it

cursorkeyboardmacos

My problem is that when I highlight some text (doesn't matter where or in which application) in order to write over it the cursor, sometimes, suddenly changes position causing a lot of typos.

Let's say I've searched the phrase "stack exchange apple" in Google.

Now I want to search for stack overflow so I first highlight "exchange" and "apple" this way:

highlighted stack exchange

and then I simply type "overflow" in order to write over the highlighted text. What I sometimes end up with is this:

wrong stack overflow

And I can assure you that I didn't press any arrow keys or trackpad or mouse button of sort. I simply wrote in the keyboard "overflow" but what happened is that after I pressed "O" the cursor changed position and the word ended up like this.

I'm running macOS Sierra v10.12.4 on a Mid-2014 15" Macbook Pro

Are there things that can fail or settings to help with this?

Best Answer

The most likely culprit once you rule out Bluetooth mouse / trackpad and any wrist or liquid input is hardware.

If you can reproduce this on a clean os install onto an external drive (to avoid wiping your normal drive and files and apps) it could be:

  • failing battery pressing underneath the trackpad
  • failing or damaged capacitive sensing grid
  • failing chip that processes the capacitive touch sensor

It's unlikely to be software, but I'd still download and install a clean and updated os to be sure unless you have close and easy access to hardware service.