A few of the Probook 450 G1 laptops that we have here at my organization have shown signs of touchpad issues. The touchpad will often be unresponsive and sparatic. If trying to click, for some reason this will type the letter s on whatever field is highlighted. We have noticed this issue on more than one of this model of laptop.
Here is a very unprofessional video of the issue. During the video, you will see that the curser will jump left and right very often and randomly. I at one point I typed a few lines of "asdf" to ensure that the keyboard is working; it was working properly. However, you will see later in the video that when I click the touchpad, it automatically types a few letter s's. I did not type those myself.
A restart will fix the issue, and it may not even happen again for months on end. When it does happen, its very hard for users to get past it. Even saving their work is interupted by the keystrokes that are brought on by this issue.