The 2 P/N differ in HW configuration in terms of assembly option (Audio Codec, WiFi)
There is no HW difference between the 2 SOMs in which can explain this issue, also as you stated it happens on a specific carrier which is suspicious.
If you wish, you can send us this carrier board with the failed SOM and we will inspect it since on our EVK I cannot reproduce it.
you can log to firstname.lastname@example.org
and open a ticket stating this issue.