MC7511: crash with traffic from Microsoft Teams

Hi,

I have an MC7511 in QMI mode managed by a python script on Linux using libqmi. It is connected to AT&T via an IPv4 PDP session. This is the router.

A WIndows 10 machine connects to the router above via WiFi. A hard crash occurs on the MC7511 when I join a Microsoft Teams call at the Windows 10 machine. By hard crash I mean that data flow immediately ceases at the MC7511 and /dev/ttyUSB2 is no longer responsive; nothing spits out in dmesg.

I’m still trying to characterize but so far this only happens with Microsoft Teams when joining a call. Teams otherwise works OK say for general chat.

I’m running the AT&T image below. Any ideas on what might cause this?

at!entercnd="A710"
OK

at!image?
TYPE SLOT STATUS LRU FAILURES UNIQUE_ID   BUILD_ID
FW   1    GOOD   10  0 0      ?_?         01.07.02.00_?
FW   2    GOOD   1   0 0      ?_?         01.07.00.00_?
FW   3    GOOD   9   0 0      ?_?         01.08.04.00_?
FW   4    EMPTY  0   0 0
Max FW images: 4
Active FW image is at slot 1

TYPE SLOT STATUS LRU FAILURES UNIQUE_ID   BUILD_ID
PRI  FF   GOOD   0   0 0      002.008_004 01.07.02.00_ATT
PRI  FF   GOOD   0   0 0      002.002_000 01.07.00.00_GENERIC
PRI  FF   GOOD   0   0 0      002.015_002 01.08.04.00_VERIZON
Max PRI images: 50


OK
at!impref?
!IMPREF:
 preferred fw version:    00.00.00.00
 preferred carrier name:  AUTO-SIM
 preferred config name:   AUTO-SIM_000.000_000
 current fw version:      01.07.02.00
 current carrier name:    ATT
 current config name:     ATT_002.008_004

OK

at+cgdcont?
+CGDCONT: 1,"IPV4V6","broadband","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0

OK