@Emilediver992 

Hi, it seems that there is no service at all on the MR600 now, please make sure the two external antennas are installed properly and try to reset the MR600 to factory defaults, then please check if it will receive any 4G signal(check signal strength LEDs and Status page of MR600).

Besides, it seems that you are not using the latest firmware now, please download the latest firmware from the website below:

https://www.tp-link.com/en/support/download/archer-mr600/v2/#Firmware

And refer to the local upgrade part in the instruction below to update the firmware and check the internet status again:
https://www.tp-link.com/en/support/faq/1667/