Ok…well apparently ifixit thinks my answer is spam. I’ll try one last time:
I think I may have the same issue, and I fixed it. I followed the ifixit guide for doing a touchpad replacement (apparently if I link to that tutorial, this post gets marked as spam, so you’ll have to find it yourself), through step 7, removing the back panel, which contains the trigger. In my case, the small metal rod that holds the trigger in place and allows it to rotate had slipped out of the hole on one side. I wiggled it back in place, and after putting everything back together it worked. It looks like this rod could easily slip out of place. Not sure if this is the same issue for you, but I hope it’s helpful. Best of luck.