@ArcherC8 

Thanks for the suggestion. I played around with channels and widths and had the same issue. But what worked was to connect on my phone to a guest network without security. I got great speeds then. But of course, I'm not going to do that on my regular network and not going to keep an open WiFi all the time. When I put a password on it, it failed to work properly again.

I played around with security settings and found that it is most likely however TP-Link is implementing WPA/WPA2 on this router that is causing the issue. I tried with it on auto, WPA, and WPA2. The only setting my phone likes is none. But only with this router. It works great on other routers/hotspots with WPA2 security

In truth, my router might be a dud because I'm having problems with another laptop on 2.4 GHz with a Teams call that I didn't have before on my old router. Speeds are acceptable for an N connection, but not consistent. I might try a factory reset and failing that, returning it and getting another one.

Any other ideas?

@InsertNameHere Same issue with my new AX 1500, I and my wife are using LG v30, connection was very fast with previous router.