Chosen Solution
My 3D touch trackpad doesn’t click on one side. It feels like there’s a bump under the left half. The middle section and right side still work like they’re supposed to. What could be the problem here?
This could be because your battery is swelling and pushing up on your trackpad. I would open up your MBP and examine your battery for swelling. MacBook Pro 13" Retina Display Early 2015 Battery Replacement
