Hi there, I was in the same boat and afraid I'd have to track down an old 1903 ISO and reinstall just to fix this silly issue. Luckily, there's an easy workaround! It's in the end of the sticky on this post:[edit]

"For those encountering issues with the touchpad driver and 1909 on a fresh install its a SUPER easy fix:

download the latest touchpad driver from here:

 

[edit]

Then attempt to install the driver (it will eventually fail saying something about it not being compatible with the OS.

Close the prompt and then go into C:\swsetup\SP99388

Then right click edit the Install.cmd (may only show up as Install) file located in that directory

Once you have that file open change This:

https://imgur.com/a/Jhj4Bvv

to this:

https://imgur.com/a/CH3r894

All you do is edit the "19H1" to say "19H2" and the two locations where it says "10.0.18362" to "10.0.18363"

Save your changes and launch HPSetup.exe, once thats done reboot and bam no more errors in the device manager."

 It worked a treat for me. Hope this helps!