5G Home internet keeps dropping!

I signed up and requested 3 gateways. I got NOKIAS  ( labeled refurbished) One at my main home just was not going to cut it with 2 bars and 7MBPS. Another at a home 30 miles away is pushing 550-600 as I can see the tower. Perfect. The other one 200 miles away at another home was awesome from install to about 3 weeks in and was also pushing 5 bars and 650-700MBPS . I have cameras, smart lights, thermostat, etc and it just started dropping off intermittently. data usage is low, and I suspect a bad unit, A new (refurbished  one) was shipped and I will install in a couple days. I just hope it lasts as I only get there 2 X /mo  but I run all my systems on it. ON a chat I was told I was getting throttled, but  for what??? 24 Gigs a month at a place I don't live at? That was not in my plan and they clarified that.  Hey, I just want consistent good service. I've heard that the NOKIAS have issues, as well as the ARKADYIANS, so what is the resolve? I was also told that broadband is controlled by my rep, and once it is full, no more  gateways would be available at the tower. But does Cell phone data  trump the gateways?

I just cant get a straight answer. I'm happy so far but if a salesperson, on a recorded line says something, it needs to be true. I love the company after 32 years with ATT, but just give me what you say you are going to give me.