When using Firefox on a touchscreen enabled laptop, I noticed that scrolling only worked using the scroll bar and I could not zoom or scroll like is done with mobile devices. I discovered a fix for this by editing the /etc/security/pam_env.conf file and adding a new environment variable.
MOZ_USE_XINPUT2 DEFAULT=1
Save, then reboot. Zoom and scrolling now work as expected on the laptop touchscreen.