I like to ask if I anyone is seeing a similar issue with the LTE modem disappearing after a Router boot or USB Modem unplugging and plugging
The Quectel USB Modem EM12 reports no SIM detected,
I have to go into the Qucetel EM12 modem and use AT commands to reset the SIM detect
What are the correct sequence to power up and power down Router say hp ac lite and a US LTE modem

Had the same issue with an EM7565 and v7b8.

I like to ask if I anyone is seeing a similar issue with the LTE modem disappearing after a Router boot or USB Modem unplugging and plugging
The Quectel USB Modem EM12 reports no SIM detected,
I have to go into the Qucetel EM12 modem and use AT commands to reset the SIM detect
What are the correct sequence to power up and power down Router say hp ac lite and a US LTE modem

First Quectel EM12 is a M.2 module and you use just USB WWAN Adapter with him and put that to regular soho MikroTik router.
You should first check if your router can work with USB port mode because probably you must change that.
Next problem is about Power, maybe consider to disable CA for testing, then lte modules use less power (check AT Commands of EM12).
Good way is first use that module with Windows, module in MBIM mode and Windows10 with proper drivers from Quectel.

I hope I give you some hints.

Many thanks for your reply
The Module and AT&T SIM works well in Windows and Linux using the appropriate MBIM and I am aware of using of QMI, This is not the issue, The problem with Quectel when plugged into Mikrotik rather say a Asus router or a Sierra Wireless router, is the RouterOS Beta causes to change the state of the Quectel SIM state, I have use every-time, AT commands to rest and toggle SIM Detect as AT+QSIMDET=1,0, I believe this is a major 7v7 Beta issue. The topic of Power, I have it monitored, I have even used Band locked B14 with no CA.

ujsd

I have use every-time, AT commands to rest and toggle SIM Detect as AT+QSIMDET=1,0, I believe this is a major 7v7 Beta issue. The topic of Power, I have it monitored, I have even used Band locked B14 with no CA.

I use EM12-G in some modules but with adapter mPCIe->M.2 and just works perfect inside SXTR/LHGR in my scenarios.
Works B14 - this means you run that usb version of EM12 or this was from PC.

Remember to run topic=lte inside logs on Ros.