Interface issue with AT&T firmware

We are using Sierra modem MC7455.
with generic firmware it gives Interface number 8 for LTE session
But with upgrade of AT&T firmware on the same device at the same index it gives interface number 0x0C but its not interface for LTE session.

Also it has been observed when same device with AT&T firmware is attached to another box it gives same interface numbers as in generic firmware.
firmware link:
source.sierrawireless.com/resou … -,027_000/

Below is the USB configuration from the device with AT&T firmware. please provide information and solution regarding the issue for incorrect interface:

=============================
Enumerating Root Hub bus 0

Node ID: 0x7F (Bus - 0x0 Address - 0x7F)
Descriptor Type: 0x1
USB Release (BCD): 0x0200
Device Class: 0x09
Device SubClass: 0x00
Device Protocol: 0x01
Translation of above: Hub
Max Packet Size 0: 0x40 (64)
Vendor Code: 0x0000
Product Code: 0x0000
Device Version: 0x0000
Manufacturer Index: 0x00 ("")
Product Index: 0x00 ("")
Serial Number Index: 0x00 ("")
Number of Configurations: 0x01

The hub at Bus:000 has 1 available ports

Bus:000 Port:0
A device is connected to Bus:000 Port:0.
Node ID: 0x1 (Bus - 0x0 Address - 0x1)
Descriptor Type: 0x1
USB Release (BCD): 0x0210
Device Class: 0x00
Device SubClass: 0x00
Device Protocol: 0x00
Translation of above: Unknown
Max Packet Size 0: 0x40 (64)
Vendor Code: 0x1199
Product Code: 0x9071
Device Version: 0x0006
Manufacturer Index: 0x01 (“Sierra Wireless, Incorporated”)
Product Index: 0x02 (“Sierra Wireless MC7455 Qualcomm”)
Serial Number Index: 0x03 (“LQ70824217031020”)
Number of Configurations: 0x01
Port Connection Status: A device is present. (0x0503)
Port is enabled.
Port is not suspended.
Port is not in an overcurrent situation.
Reset signalling is not being asserted.
Port Power is not in the powered of state.
Device is attached as a HIGH SPEED device.
This device is not in Port Test Mode.
Configuration index 0:
Config Descriptor Length: 0x09
Config Descriptor Type: 0x02
Config Descriptor Total Length: 0x00D8 (216)
Config Descriptor Number of Interfaces: 0x05
Config Descriptor Configuration Value: 0x01
Config Descriptor String Index: 0x0000 ("")
Config Descriptor Attribute byte: 0xA0
Device can be bus powered (valid only for usb1.x)
Device cannot be self powered
Device does have remote wakeup capability
Config Descriptor Max Power: 0xFA (500 ma)
--------------------------
Configuration Interface 0
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x00
Interface Alternate Setting: 0x00
Interface numEndpoints: 0x02
Interface Class: 0xFF
Interface SubClass: 0xFF
Interface Protocol: 0xFF
Translation of above: Vendor Specific
Interface Index: 0x00 ("")
Endpoint Index: 0
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x81
Endpoint number: 0x01
Endpoint Direction: IN
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
Endpoint Index: 1
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x01
Endpoint number: 0x01
Endpoint Direction: OUT
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
--------------------------
Configuration Interface 1
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x02
Interface Alternate Setting: 0x00
Interface numEndpoints: 0x03
Interface Class: 0xFF
Interface SubClass: 0x00
Interface Protocol: 0x00
Translation of above: Vendor Specific
Interface Index: 0x00 ("")
Endpoint Index: 0
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x83
Endpoint number: 0x03
Endpoint Direction: IN
Attributes Mask: 0x03
Transfer Type: Interrupt.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x000A (10)
Interval: 0x09
Endpoint Index: 1
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x82
Endpoint number: 0x02
Endpoint Direction: IN
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
Endpoint Index: 2
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x02
Endpoint number: 0x02
Endpoint Direction: OUT
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
--------------------------
Configuration Interface 2
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x03
Interface Alternate Setting: 0x00
Interface numEndpoints: 0x03
Interface Class: 0xFF
Interface SubClass: 0x00
Interface Protocol: 0x00
Translation of above: Vendor Specific
Interface Index: 0x00 ("")
Endpoint Index: 0
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x85
Endpoint number: 0x05
Endpoint Direction: IN
Attributes Mask: 0x03
Transfer Type: Interrupt.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x000A (10)
Interval: 0x09
Endpoint Index: 1
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x84
Endpoint number: 0x04
Endpoint Direction: IN
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
Endpoint Index: 2
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x03
Endpoint number: 0x03
Endpoint Direction: OUT
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
--------------------------
Configuration Interface 3
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x0C
Interface Alternate Setting: 0x00
Interface numEndpoints: 0x01
Interface Class: 0x02
Interface SubClass: 0x0E
Interface Protocol: 0x00
Translation of above: Communications and CDC Control device
Interface Index: 0x00 ("")
Endpoint Index: 0
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x87
Endpoint number: 0x07
Endpoint Direction: IN
Attributes Mask: 0x03
Transfer Type: Interrupt.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0040 (64)
Interval: 0x09
--------------------------
Configuration Interface 4
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x0D
Interface Alternate Setting: 0x00
Interface numEndpoints: 0x00
Interface Class: 0x0A
Interface SubClass: 0x00
Interface Protocol: 0x02
Translation of above: CDC-Data device
Interface Index: 0x00 ("")
--------------------------
Configuration Interface 5
Interface Descriptor Length: 0x09
Interface Descriptor Type: 0x04
Interface Number: 0x0D
Interface Alternate Setting: 0x01
Interface numEndpoints: 0x02
Interface Class: 0x0A
Interface SubClass: 0x00
Interface Protocol: 0x02
Translation of above: CDC-Data device
Interface Index: 0x00 ("")
Endpoint Index: 0
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x86
Endpoint number: 0x06
Endpoint Direction: IN
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00
Endpoint Index: 1
Endpoint Descriptor length: 0x07
Endpoint Descriptor Type: 0x05
Endpoint Address Mask: 0x04
Endpoint number: 0x04
Endpoint Direction: OUT
Attributes Mask: 0x02
Transfer Type: Bulk.
Synchronization Type: No Synchronization.
Usage Type: Data Endpoint.
Maximum Packet Size: 0x0200 (512)
Interval: 0x00