ulpm doesn’t work with legato 19.04.0 and ulpm firmware version/ mcu version 002.011.
It WORKS with legato 19.02.0 and ulpm firmware version/ mcu version 002.009.
Please fix this issue in the latest release.
https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-latest-release/