It may be related to driver issue
3 figure works on my lenovo laptop without any manual configuration.

Hi, chair96, is any effect when you tap your touchpad with 3 fingers now? If it cause into 'window move mode', then it explains that your touchpad can works well with multi finger gesture, but only not cause the effect what you want.

In fact, the default setting of 3 finger-tap 'was' middle click until a update in end of 2017, because the deepin team enable the tap gesture feature in this update, witch conflict with the default setting by synaptics driver. But we can still achieve the goal by edit the config file of gesture feature, in the path of /usr/share/dde-daemon/gesture.json like this:


What you need to do is edit the config file, replace the default 3 finger tap setting with


ensure the xdotool command has installed in your system, then reboot your laptop, and it should be works with middle click when tap use 3 finger.
Note that this config file might be changed in future update, so you should check the file after update if the effect of 3 finger tap back to 'windows move mode'.