UBUNTU + 3 PROXY : 4g proxy server. improvement is needed

What we currently have and how it works/worked: • Server with Ubuntu 16 installed. There are 20 dongles (Huawei E3372h) connected through USB, each dongle got simcard in it. • Each of these dongles are rebooting every 2 minutes via script. With every reboot mobile IP of that simcard changes. • Each of these dongles got web interface that can be accessed via browser by entering their IP address from server’s machine or when connected to that specific dongle via proxy manager from different machine. • Each of these dongles were configured by “3proxy” software. • Each dongle had same ADMIN credentials/authorization data but different GUEST user authorization data. • ADMIN user got no restrictions and could access dongles web interface while GUEST user could only use mobile internet but would be denied to access dongles web interface. • I could connect to each dongle by server IP + port via any proxy manager (e.g. foxyproxy). • When dongles_xx simcard had mobile internet bough I could connect to that dongle/proxy use its mobile internet. Websites would see my IP as that dongle IP. • Before Ive see each of 3proxy configuration files running in the background, now they’re not there any more and proxy does not work. • When server pc was restarted all settings would stay and everything would load up automatically. TO DO LIST Carefully read everything and check out server to get familiar with the setup. Then fix all what is not functioning correctly. 1. To Investigate and fix error that shows up from time to time. I assume it’s something to do with usb ports and dongles. 2. Each dongle configuration must allow only admin user to be able to access dongles web interface or other sensitive servers data. Guest users can only use mobile internet of the dongle. 3. Change dongle reboot timer from 2 minutes to 1 hour for each dongle DESIRED END RESULT: Server works without any errors and after restart everything stays the same and loads up automatically. There would be no automatic updates happening so nothing gets accidently changed. Server got no graphical interface and junk software (libre office etc…) on it, only required programs/ dependencies are installed. This server is purely proxy server! This proxy server will accept commands from other server via SSH so if any of dependencies for that are required they are installed/left untouched. All dongles and proxy usage operated like described in “what we currently have and how it works” section. Except for few things that must be changed described in to-do list.