@rareravi try different com ports. As for as I can remember ZTE AC8700 didn't use to show the values for some reason and I guess I chose another port and it did. Not sure.
Solved. I should have used service port. Now it display proper values.
Getting poor speed around 60kbps to 500kbps with Rssi -78dB and ec/io -3 to -8dB.Do you think changing to different modem (rev A) will make any improvement in speed and signal reception?