@StretchOnBass Thanks!!!  I had the same problem and luckily found your post.  Seems to defeat the purpose of "mixed mode" but whatever.

@StretchOnBass 

I am having a issue that sounds familure but not sure.

I have 6 switches, 1 dimmer, 4 plugs and 1 camera all connected to my ASUS 1200ac router, the router is connected to a TP-Link range extender through the LAN jack and the range extender is connected to either my wife or my phones hotspot.

My wife and I used to have Sprint cell service and everything worked as it should with no issues. I had to swap my SIM card and they gave me a T-Mobile SIM. Thats when the issues started to happen.

When using the hotspot from my wifes phone everything works as it should but when I turn my hotspot on all my smart devices go into local only mode. As mentioned the ony thing that changed was the service provider and nothing else.

I hope your issues can help me out as I am growing frusterated trying to figure out the issue.