endstops were tested. gantry stops at endstop and then moves back up. If the endstops stop working the motors keep moving the part. That did not happen.
It clearly registered the endstop.

I realise you only google stuff martin, but I tend to go more on 8 years experience with 6 different 3d printers - actual real world experience.
And as a rule when endstops stop working, they just stop working. 90% of the time it's the wiring, the actual switches are such simple and robust mechanisms that they tend not to die.
Everything here indicates that the endstop is fully functional.

Seems pretty clear.