Touchscreen disabled to stop ghost bubbles and erratic pointer and still happening

2 year-old Inspiron 5779, Windows 10 Home with screen bubbles on right and erratic touchscreen.  Was advised by level 3 Microsoft tech to disable the HID Human Interface touchscreen to fix (was advised that would lose touchscreen which I could live with), now it's happening again.  Microsoft reinstalled Windows and it didn't fix issue. Touchscreen disabled and touchscreen driver shows as hidden. Tried uninstalling and reinstalling, but it shows as disconnected when troubleshooter ran.  Microsoft says it's a hardware issue.  Would this be covered under Dell extended warranty?