This is it… It’s called a detent (I’ve no idea why)
Above is not actually the one I seen last year as the guy was selling them. Might be worth a look in eBay.
I was having an issue with my HOTAS when I got it. It was lifting up off of the desk (I don’t want to screw it down into my very expensive oak corner desk). I went to my local sheet metalist and they made me 2 bespoke 10mm steel plates with corresponding screw holes which they sprayed black. Needless to say they didn’t move once I attached those but I worried about scratching the desk and so bought a couple of mouse mats then stuck them in to the bottom using rug grippers.
I also found the spring in the stick wasn’t resistant enough (I got my setup off of Facebook for a steal and there was only one available). I found a local spring manufacturer and he made me two custom springs with the perfect amount of tension (and he didn’t charge me).