Comment 10 for bug 1651005

I was having the same problem, I think, with a very new schenker h507 (p651rp6, essentially your same laptop) using arch linux. It got fixed magically by enabling arch "testing" repository, which contains very recent versions of linux-firmware, libinput (I'm not using synaptics) and others. Now my touchpad (and everything else) works. Sorry for not being more specific as of which package update fixed it - I'm moving forward now from this. In any case, this means that the problem is already fixed and the solution will eventually make it to the main distros. If you cannot wait, you could give arch (with the testing repo enabled) a try (using antergos to install makes it a breeze). Let me know if you need more help.