Hmm, I’m not sure why you would have this on your first install but lost it–that is odd. Is libinput-gestures installed?
Are there any relevant options in your mouse settings?
Settings Manager > Mouse and Touchpad > Device=(select Touchpad) > Touchpad tab, and set Scrolling Mode = “Two-finger scrolling”
If not, it might be worth installing something like Fusuma or Touchégg like these guys: OSX-style trackpad gestures in Linux