not really clear what you’re asking for, to be honest.

So it doesn’t matter per se whether it’s a 4g router, other than the fact that a lot of those services won’t give you a publicly routable IP. Is this device a windows or Mac device? You can use things like Chrome remote desktop to completely obviate the need for anything particularly fancy.

If you’ve already doubled checked the coax connections being nice and tight, call your isp. It’s almost certainly a signal level issue or something else on their end.