So my Xbox controller connects to my phone and works fine but when connect to my Xbox if...

Yes, I'm trying to connect my controller via Bluetooth on my Windows 10 PC (It worked before yesterday). When I connect my controller via USB Cable it works fine.

The XBox Button flashing slowly when it's turn on. When I press the sync button to connect via Bluetooth, the XBox Button flashes for 1 second and the controller turn off.

When I connect a wireless controller, the left analog stick is stuck in down position. This is brand new controller, and have had other controllers do the same . But if I connect these controllers with a cable they work fine. Does anyone know
of a way to make it where I can use wireless controllers with my system, so my family can play games with me again

Are you connecting these wireless controllers via Bluetooth, or using the Xbox Wireless Adapter?

If the controllers are working fine when connecting via wire, then it sounds like the controllers themselves are fine, and it's possibly a driver issue, or a wireless connection issue.

Hey, it's me again. Wanted to add some more information. After trying the steps you listed, I decided to connect the controller to my iPhone via Bluetooth. It successfully connected to my iPhone and was working just fine with cloud gaming. Next I disabled the Bluetooth on my phone and attempted to sync the controller back to my Xbox. It appeared to sync fine with the Xbox but still not working, unable to move or click on anything. Very strange 🤷‍♂️

I am using a wireless connection on a netgear wndr4000 and my modem is an arris modem tm702g however i don't think my modem or router are the issue as all of my computers, phones, ipad and kindle can all connect fine and when I do the connection test on
my xbox it says everything is working fine.

Try connecting your Xbox app to your Xbox and then your controller to your phone, and using remote play I fixed it then just connected my controller back to my Xbox. It worked for me.