Cannot Reliably Connect Devices Home Internet

I have both Verizon LTE home internet and T-Mobile Home Internet up now as well.  Verizon is about 50-60Mbps download and about 6 Mbps upload.  T-Mobile (4G) is about 140 Mbps download and 10-50 Mbps upload.  But T-Mobile just doesn't work on a lot of websites, and is not at all reliable with any streaming boxes or Televisions.  I am in a 5G area so once T-Mobile turns on 5G for home internet it's going to be even faster I think.

So for now I'm keeping both and switching as I need to between them.  I am hoping in the coming few weeks they fix this.  Right now this new Router is fantastic in performance, but very flakey in actual practice.  And not very compatible with devices or across all websites.