Contact: jelmer@beyond.io
Issue: see https://devzone.nordicsemi.com/f/nordic-q-a/61681/nrf9160-doesn-t-connect-over-nb-iot-ibasis-and-t-mobile-works-fine-on-cat-m
Description: This is the trace with the T-Mobile sim inserted and the T-Mobile APN set (iot.nb). This sim connects and works in a BG96 modem at my location (N California US). PCO is off (exactly same results with PCO on). Modem seems to give up looking for cell towers.

MFW: mfw_nrf9160_1.2.0
Serial log file: 2020-05-26T18_18_51.892Z-log.txt
Modem trace: trace-2020-05-26T18-18-46.930Z.bin
nRF91 DK version: PCA10090 0.9.0 960021495

$ west list
manifest     nrf                          HEAD                                     N/A
zephyr       zephyr                       9bab3a84b6427662a1d3df45db365d23f2eeaa3a https://github.com/NordicPlayground/fw-nrfconnect-zephyr
mcuboot      bootloader/mcuboot           19dce6e3034ac546dba03d523cbd0f7784f5e0e2 https://github.com/NordicPlayground/fw-nrfconnect-mcuboot
mcumgr       modules/lib/mcumgr           4d589cc0fe4783d49f9f0cc62a0bfdb2ad3da8df https://github.com/NordicPlayground/fw-nrfconnect-mcumgr
nrfxlib      nrfxlib                      3eed8cbd8f6b0fa38aaa6b7d5d0e33bd7408f0d1 https://github.com/NordicPlayground/nrfxlib
cmock        test/cmock                   c243b9a7a7b3c471023193992b46cf1bd1910450 https://github.com/ThrowTheSwitch/cmock
unity        test/cmock/vendor/unity      031f3bbe45f8adf504ca3d13e6f093869920b091 https://github.com/ThrowTheSwitch/unity
mbedtls-nrf  mbedtls                      mbedtls-2.16.4                           https://github.com/ARMmbed/mbedtls
cmsis        modules/hal/cmsis            bfa48a337e6fe08187d86f7ba7bbca0626475e17 https://github.com/zephyrproject-rtos/cmsis
canopennode  modules/lib/canopennode      5c6b0566d56264efd4bf23ed58bc7cb8b32fe063 https://github.com/zephyrproject-rtos/canopennode
ci-tools     tools/ci-tools               cf55a47d52d38af655f3efa6d38ff105b727358a https://github.com/zephyrproject-rtos/ci-tools
civetweb     modules/lib/civetweb         99129c5efc907ea613c4b73ccff07581feb58a7a https://github.com/zephyrproject-rtos/civetweb
fatfs        modules/fs/fatfs             9ee6b9b9511151d0d64a74d532d39c6f2bbd4f16 https://github.com/zephyrproject-rtos/fatfs
hal_nordic   modules/hal/nordic           1ebfdf148b2ca1d9ab9267ab2cd64cc00f32d505 https://github.com/zephyrproject-rtos/hal_nordic
hal_st       modules/hal/st               fa481784b3c49780f18d50bafe00390ccb62b2ec https://github.com/zephyrproject-rtos/hal_st
libmetal     modules/hal/libmetal         60f40977eccb7e067a83933cec859e266bff4849 https://github.com/zephyrproject-rtos/libmetal
lvgl         modules/lib/gui/lvgl         74fc2e753a997bd71cefa34dd9c56dcb954b42e2 https://github.com/zephyrproject-rtos/lvgl
mbedtls      modules/crypto/mbedtls       cf7020eb4c7ef93319f2d6d2403a21e12a879bf6 https://github.com/zephyrproject-rtos/mbedtls
net-tools    tools/net-tools              1080094bc246357c6c35e80e8b2d5d0ce7e0d963 https://github.com/zephyrproject-rtos/net-tools
open-amp     modules/lib/open-amp         5720c73ef3bd885824b2d2184f606443e03f73c4 https://github.com/zephyrproject-rtos/open-amp
loramac-node modules/lib/loramac-node     29e516ec585b1a909af2b5f1c60d83e7d4d563e3 https://github.com/zephyrproject-rtos/loramac-node
openthread   modules/lib/openthread       2ac83762b87b9cbb7072e3bca663ac13708c17d9 https://github.com/zephyrproject-rtos/openthread
segger       modules/debug/segger         6fcf61606d6012d2c44129edc033f59331e268bc https://github.com/zephyrproject-rtos/segger
tinycbor     modules/lib/tinycbor         40daca97b478989884bffb5226e9ab73ca54b8c4 https://github.com/zephyrproject-rtos/tinycbor
tinycrypt    modules/crypto/tinycrypt     3e9a49d2672ec01435ffbf0d788db6d95ef28de0 https://github.com/zephyrproject-rtos/tinycrypt
littlefs     modules/fs/littlefs          0aefdda69d236cb01f932117c1f32e9da09c0ec3 https://github.com/zephyrproject-rtos/littlefs
mipi-sys-t   modules/debug/mipi-sys-t     baf51863f19f009b92e762115ba5572a5b996b92 https://github.com/zephyrproject-rtos/mipi-sys-t
nrf_hw_models modules/bsim_hw_models/nrf_hw_models fec69703cb1ca06fcdab6d5fde01274f0fc5c759 https://github.com/zephyrproject-rtos/nrf_hw_models
edtt         tools/edtt                   c39888ff74acf421eeff9a7514fa9b172c3373f7 https://github.com/zephyrproject-rtos/edtt