Samsung Galaxy S6: How to fix inverted touchscreen issue (X axis)

Only if the two lines from top are displaying different values for PARTS and PHONE firmware then:

1. Dial *#2663# in the dialer
2. Click on TSP FW UPDATE (General) it shouldn't need a reboot
3. Make sure PARTS and PHONE show the same values
4. Inverted Touch Screen Fixed

If code doesn't work, try to flash first with another firmware. Right now I'm testing various FW versions, so keep refreshing this page.