u-blox LARA R204 causes ModemManager abort exit

[Matthew Starr]

I am using a u-blox LARA R204 modem with ModemManager 1.8-rc2.  I am running this in a buildroot generated Linux install on an embedded device. The LARA R204 is a Verizon 4G LTE only modem with no 2G/3G fallback (https://www.u-blox.com/en/product/lara-r2-series).

When ModemManager starts up, the modem is probed, the Device ID obtained, and then right after AT+URAT=? is sent and a response is returned, ModemManager exits with the following:

ModemManager[424]: <debug> [-192499452.090358] (ttyACM0): --> 'AT+URAT=?<CR>'
ModemManager[424]: <debug> [-192499452.092150] (ttyACM0): <-- '<CR><LF>+URAT: (3)<CR><LF><CR><LF>OK<CR><LF>'
**
ERROR:ublox/mm-modem-helpers-ublox.c:817:mm_ublox_get_modem_mode_any: assertion failed: (any != MM_MODEM_MODE_NONE)
Aborted

This same error occurs every time ModemManager is run.  I compiled with the options --without-qmi and --without-mbim since they are not used by my modem.

Best regards,
Matthew Starr