Why is it my 5G Internet Gateway can't work using 5G?

I've had two gateway devices - both had problems.  I get great 4-5 bars but terrible network.  Have sent both back and using Comcrap again.

Here’s what I was told by tech support (note: since the story seems to change with every call, YMMV):

1.  The radios work great to the towers, but all 4 towers in my area are having network problems with no date for resolution.
2. When asked why I get good 5g on my phones, was told:  "we prioritize phone traffic" during times of congestion.  Since the towers stay congested due to our network problems, you will not get good internet until we fix it.  No ETA for that.
3. I asked why I could not stream a movie or even listen to a song over the internet without having the signal drop out.  They checked and said that I was being throttled - I suppose because I was, well, using the internet.  I was surprised that they throttle (which means zero Internet) when the problem is theirs.

My takeaways,  TMO is great for phone but terrible (for now) for Internet.  Verizon is offering 5g on their network with up to 1GBs for less cost than TMO - so trying them next is a no brainer.  Maybe the "carrier" will do a better job than the "un carrier"