Any way to disable 5G connection on router?

Just curious. You state when the 5G is up but what band does it connect to and how is the signal strength and quality and signal to noise ratio? If you are only 3.5 miles away it would be interesting to know if it is linking to the (NR) band n41 (2.5 GHz) or the  n71 (600 MHz). If it is the mid tier 2.5 GHz at 3.5 miles out that might be part of the problem as the mid band is at the fringe at 3.5 miles. I bet the signal strength is pretty low if it chokes down like that. The 4G LTE running at 35-50mb/s range seems about right. When user load builds the QoS they use probably comes into play. I connect to an n71 5G signal 5.3 miles out and even in the evening with more load we still have pretty solid traffic flow. 

There seems to be a fundamental problem there. The 5G should out perform the 4G LTE for speed. When the 5G signal here falls the 4G LTE signal is a real dog. Sure it will connect but is slow as a snail's pace. I took great pains to find the best window for the router and rotated the can to expose the antennas so the 5G secondary signal is the strongest one.