Motorola G5 Plus CDMA problem solved
GOOD NEWS for Moto G5 plus owners.
I've been running all the above mentioned circles trying to activate my Moto G5 plus on TPO CDMA.
Found a simplest solution: order SIM kit 3 in 1 for that phone from TING.
Got it, installed it - phone is activated.
It will cost you $9.99 - but it works.