Question: Trackpad two finger scrolling and right-click issue with Ubuntu 17.10 (i386, 64bit, GNOME 3.26.1) on a Lenovo T540p (the model with a Intel Core i5-4210M Haswell CPU etc)

Answer: 
I have the same issue on my Thinkpad T450s. This issue is referenced on launchpad here: <https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1722478>

It seems to happen after a resume. The workaround described on LP1722478 works for me:

```
sudo modprobe -r psmouse
sudo modprobe psmouse

```
I had the same problem. In Gnome Tweaks, 'Keyboard & Mouse' settings, changing the click method to 'Areas' got the right-click working again.