of course:
Before your tests, the US number does not works. (10 fail, 0 OK)
After your tests, the US number work half of time (5 fail, 5 OK)
Now (7h17 FR time): ( 8 fail, 2 OK)
a big thanks to my REDIAL button landline phone => no KB number bad typing error 
for sure, it is a connexion problem between my classical FR provider and your US gateway *OR/AND* your US gateway and your PL partner.