Hey, this is because the Firefox's pinch gesture has been mapped to page zoom – this shouldn't normally be set by default but it's possible it got changed somehow. To fix it go to about:config (in the url bar), search for "browser.gesture.pinch" and reset those fields to default (right click -> reset). Then it should work :)

I'm happy to hear you like it, thank you :)!

I think a recent Firefox update has broken it. I’ll see if it can be reenabled