The issue has been resolved. Re-calibration (again) did the trick.
When I touch the screen like a mouse click, it seems to behave as if I did a double click. I press a toggle button for example to turn a switch on or off and it completes the full cycle of on then off instead of on only. Any ideas of why a single touch behaves like I'm touch something two times? Thank you.
P2418HT, touch click event does not work