Switched to 5G but now roaming at home

New iPhone 12. BM switched me over to 5G, except now I am roaming even when I am at home. I had great (unsure if it was 3G or 4G ) service with BM on my old iPhone X. My partner who has ATT gets 5G no problem. 

I’m in San Francisco in a area that has no issues with connectivity.

BM support sent me the new SIM and the phone has been activated without issue.

If I turn off roaming, I don’t get connectivity.  Forget telling me to use WI-FI. If I wanted to do that, why then do I even pay for Boost? It should work without roaming in my home. 

I’m stuck and the only option left is to ditch Boost. This my last attempt at fixing it.

Both me and my partner are extremely technical people. This isn’t an issue of a BDU (support term for Brain Dead User). We’ve tried all the options. It feels like Boost’s 5G just isn’t ready for prime time?