Touchpad Not Vertically Scrolling Smoothly in Acer Spin 513 - CP513-1H-S60F Chromebook.

I have Acer Spin 513 - CP513-1H-S60F.

After 18 months of using it, the touchpad vertical scrolling barely works now. It struggles to move. Horizontal scrolling still works fine on the touchpad and both with an external mouse.

I cleaned the Chromebook including the touchpad with a damp cloth as I have been doing since I got it. I did a hardware reset but not sure if successfully. I power washed it twice. No luck unlike one other person in Google Help that had a virus.

I don't know how all of a sudden, my touchpad is failing when I haven't done anything different. I am hoping it isn't a hardware failure so can be fixed.

Any suggestions?

[Edited the thread to add model number to the title]