An additional piece of information: If I switch from wayland to xorg X server, the touchpad works as expected. The synaptic entires in Xorg.0.log are:
[ 64.070] (II) LoadModule: "synaptics" [ 64.070] (II) Loading /usr/lib/xorg/modules/input/synaptics_drv.so [ 64.071] (II) Module synaptics: vendor="X.Org Foundation" [ 64.071] (II) Using input driver 'synaptics' for 'SynPS/2 Synaptics TouchPad' [ 64.112] (II) synaptics: SynPS/2 Synaptics TouchPad: found clickpad property [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: x-axis range 1472 - 5664 (res 42) [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: y-axis range 1408 - 4682 (res 52) [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: pressure range 0 - 255 [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: finger width range 0 - 15 [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: buttons: left double triple [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: Vendor 0x2 Product 0x7 [ 64.112] (--) synaptics: SynPS/2 Synaptics TouchPad: touchpad found [ 64.148] (**) synaptics: SynPS/2 Synaptics TouchPad: (accel) MinSpeed is now constant deceleration 2.5 [ 64.148] (**) synaptics: SynPS/2 Synaptics TouchPad: (accel) MaxSpeed is now 1.75 [ 64.148] (**) synaptics: SynPS/2 Synaptics TouchPad: (accel) AccelFactor is now 0.038 [ 64.148] (--) synaptics: SynPS/2 Synaptics TouchPad: touchpad found
