Sorry, my fault. Today I saw in GNOME-Tweaks that the setting for Mouseclick-Emulation was 'Finger' instead of 'Area' (I have a German Version, sorry for not knowing the correct English Words in the menues). Finally I can say, that the Touchpad works perfect in Ubuntu 18.04 LTS by running
$ sudo apt install linux-generic-hwe-18.04-edge
Sorry, my fault. Today I saw in GNOME-Tweaks that the setting for Mouseclick- Emulation was 'Finger' instead of 'Area' (I have a German Version, sorry for not knowing the correct English Words in the menues). Finally I can say, that the Touchpad works perfect in Ubuntu 18.04 LTS by running hwe-18. 04-edge
$ sudo apt install linux-generic-
Thanks a lot to Kai-Heng Feng! :-)