I have the same problem on my Thinkpad x240 with Ubuntu 20.04
Linux E5450 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
This kernel parameter workaround "psmouse.synaptics_intertouch=0" work in the meantime (forever since it's 3 years old bug ??)
I have the same problem on my Thinkpad x240 with Ubuntu 20.04
Linux E5450 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
This kernel parameter workaround "psmouse. synaptics_ intertouch= 0" work in the meantime (forever since it's 3 years old bug ??)