Mouse right click intermittently stops working on macOS I am using macOS 10.15.4 &quot;Catalina&quot;, and intermittently my mouse right click starts behaving like a mouse left click; i.e. no matter how I configure my mouse, I cannot get the right click (secondary button) behaviour. It is an Apple USB non-cordless mouse; the Mac came with a cordless mouse but that died.
It usually comes good after unplugging and replugging the mouse from the USB port, a few times.
It is possibly a hardware issue, but if it is, why does right-clicking do anything at all?
Probably the only &quot;uncommon&quot; way I use my Mac is I leave the emacs editor constantly running; emacs is a huge program and I guess there is a chance it is doing something strange.
Is this a known issue? Or does it sound like a hardware issue?
In fact it was a hardware issue. I confirmed this by waiting for the behaviour to reappear, then plugging the mouse into a different computer. (See comments below the question).