Strange touchpad response problems--intermittent functionality

I have a Dell Latitude E5420. Sometimes I have really bad problems with the touchpad. The sensor is not responding well and so the pointer is hard to move across the screen. Looking at the touchpad icon in the system tray (which turns blue when it notices input), the icon keeps switching between blue (input) and grey (no input) really quickly as if there is a loose connection.

So I figured the sensor is broke and I need a new one.

But... The problem only occurs after I have had the computer on for at least 10 minutes and sometimes it does not occur at all. Further, sometimes restarting the computer will help reduce the problem, even if only for a short period. Last, the problem seems to get worse the longer I keep the computer on. For the first 5-10 min I might notice no problems, then it gets worse and worse until after 30 minutes I cant even use the computer at all. But then again sometimes I can run the computer for 2 hours before having problems. It's random.

So then I thought that maybe it was a resource problem--that is there is not enough CPU resources or RAM to process the mouse. But that's not it. My average CPU usage when browsing the net is about 10% or so, and I have plenty of free RAM.

So this is a strange problem as it really seems like a hardware issue up front, but it also has symptoms of a software issue.

I have used SlimDrivers to update all my system drivers including the BIOS. Running Windows 10.