Check and fix openwrt configuration on router

Job ID: 33367776

Budget: $30 – $250 USD

I have 5 x wifi routers with each 4 x simcards, 4 x 4G PCIe modems built-in.
There is a factory configuration on the router but I am having problems with the 4G connections. The modems keep connecting and disconnecting and it is not the signal because I have other LTE modems in the same office that I get good speeds up and download.
I need a stable, high as possible speed connection and equal load balancing between the 4 modems.