Antenna aftermarket for MKR1400

I’m looking for a solution to gain reception so I’ve decided to buy this external antenna and relative cable.
The problem is that my application work perfectly with original arduino antenna but not with the aftermarket!
If i made the gsm scan test sometimes the aftermarket antenna runs and sometimes no, and running my code it is impossible to connect to gsm.
The question is: the problem depensd on power supply?
the problem depns on not compatible antenna?

As power supply i use th USB with PC or charger.

Thansk for any help or suggestions.

Antenna is science. I would say you have to find a superdude (not me) for antennas to tell you which antenna is possible to attach. In general your new antenna makes the mkr not a stronger sender (you also need to send) so in my humble opinion: use the original antenna and let loose.