Maybe add this as tutorial, idk
So the Lenovo Ideapad 5 14 and 15 (LI515) have touchpad issues. This was a fix for the LI515. But this only worked with the widely used Elan touchpad. Mine for some reason was a synaptics touchpad, but similarly it would fail sometimes.
To fix this you can simply reload the i2c_hid module:
sudo modprobe -r i2c_hid && sudo modprobe i2c_hid