Hi Snodherm
I noticed there is an updated touchpad driver for this model from May 2018. I would apply that to see if it resolves the problem:
https://download.lenovo.com/consumer/mobiles/bc...
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.