There seems to be an incompatibility between this build and manjaro-arm-flasher. I use etcher to flash PHOSH on my SD card, and then use manjaro-arm-flasher from there to flash PLASMA updates to the eMMC. Below are the details I initially logged in the PLASMA thread; not the best place in hindsight.
EDIT: Applied a few updates today (including phoc/phosh) hoping it might help my issue, but manjaro-arm-flasher aborted with the same details when run from the terminal; including after a reboot and after reinstalling manjaro-arm-flasher (via pamac GUI).