Xbox one x controller causes lag

Not much we can do for you here but you can contact support here:
https://beta.support.xbox.com/contact-us

Same thing happens with my phone, but not my PC strangely

My One X controller disconnects after a few minutes of being paired to my computer, causing a
HUGE lag spike in any game I am playing. I have tried both Bluetooth
and the official controller dongle from Microsoft. A lot of other people have been having the same issue, and I wanted to know if there is a windows patch or workaround that I can download. As everybody
knows, one you wire it directly (via micro usb) all the problems go away. I did not pay extra for the adapter to just wire it directly, and frankly I am very frustrated with microsoft's
utter lack of support; always claiming that it is your fault that the device is not working correctly, then not replying anymore and locking the post.

Your pc have the Bluetooth on main board or you are using an external Bluetooth module? Is your window fully updated? Most of this problem in computer are from drivers of peripheral. I will do a full drivers review to see if there are some updates or if
2 drivers are in conflict. Also the interference could cause disconnection. Disconnect all peripheral you don't need st the.moment and see if thr problem still there or if worse or better. Unfortunately this is a long process of analysis like most of computer
problems are and don't have in hand the hardware isn't easy to help you

If you still have a warranty on the controller, try returning it. I hope you get it to fix soon!

Do you have any other bluetooth or wireless devices nearby that could be interfering with it?