Loosing MQTT connection

I am using Quectel ec200t in elevator service and the connection is good, until the elevator moves up or down in shaft, sometimes (15% chance) i lose MQTT connection to server when the device is moving (device and antenna are in shaft on top of cabin). I am using antenna as shown in picture (in case you cant see visit this linkhttps://m.media-amazon.com/images/I/51AsXXHBnwL.AC_UF1000,1000_QL80.jpg . i power device with 5v 2.5A block and using lm338 regulator to provide voltage for quectel (3.7V). so i guess that problem is in power consumption because while moving i can see little voltage drops on main 5v block.

if someone faced that type of problem please help. why i am loosing connection?

Hi @kaxa_gvimraze
Can you monitor the VDD pin voltage continuously? If it’s always 3.7V it should be fine.