upload and download speeds all over the place on 5GUC and T-Mobile Internet over 5G UC

Unfortunately, its a lot easier to set bands on Samsung devices.  I.e. I can disable n71 SA/n71 NSA , which often causes performance issues where I am.  In rural communities where there aren't many T-Mobile subscribers, n71 is a good boost (adding 15x15MHz to midband LTE).  Eg.  Northern MI T-Mobile has 15x15 n71, 5x5 LTE B4, 5x5 LTE B12. speeds would be ~20Mbps 'at best' in many areas on B12, and B4 has shorter range.  n71 15x15 would give … upto 150Mbps.

In urban areas, however, range can be the enemy.  In my area, there is 15x15 n71,  100MHz (TDD) n41, 15x15 B2 LTE, 20x20 B4 LTE, 5x5 MHz B12 LTE, 2x20MHz B41 LTE, 10x10 B71 LTE.

The extra piece is that midband operates 4x4 MIMO, while low band does not.

This effectively gives 15x15 n71 the same throughput as 15x15 B2.  ~150Mbps/50Mbps under ideal conditions.

B2 + B4 + B71 ≈ 400Mbps/50Mbps

B2 + N71 ≈ 220Mbps/50Mbps

B2 + B4 + N71 ≈ 300Mbps/50Mbps 

B2 + n41 ≈ 1200Mbps/115Mbps

B4 + n41 ≈ 1250Mbps/135Mbps

B2 + B4 + n41 ≈ +1400Mbps/140Mbps (max seen 1687Mbps/137Mbps)

I’ll note here, that I do not get 5G ‘at home’ except outdoors, and then its a weak n71 or n41.

As a result, I disable n71.

If you have strong n41, sites are being upgraded… it will help.  If you're near a really busy area, and a lot of people are using it… its like an overloaded cable internet node.