Geetech Prusa i3 Pro A - Z Axis Problem

[Ilankt]

Hello
I'm having problems with my Z Axis. It seems that sometimes one of the two motors is "stuck" and then only one of them moves,
so everything is getting messed up.
after a 10mm height of printing I measured the difference between the two motors and it reached up to 3mm.
By Stuck I mean that I hear like a weird clicking noise, it tries to rotate but not successful.
I did check the height of each motor at start (Home position) and it's the same position (0.1mm resolution caliper).

Help???

[bang]

Did you solve it?
If you didn't,you can have a look at the attached file:

I3 Z axis.zip

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