@ericp502 

Regarding the VPN disconnect and download issue, can I know how you use the VPN? Are you setting up the VPN Client feature on the AX21 as described here? Is the internet connection on the AX21 stable if you are not connecting to the VPN server? Which device are you running the VPN connection on, is it a computer or phone? Does it connect to the 5G or 2.4G network when the VPN disconnects? When you connect a device to the router, Smart Connect will automatically identify the best available channel and assign the device to it. It allows the router to automatically choose the most efficient device so that every device is able to reach its full potential. Which network does it connect after you disable the Smart Connect?

Regarding the WMM concern, can I know the reason why you want to disable the WMM on the router? WMM function can guarantee the packets with high-priority messages are transmitted preferentially. Remember that WMM is a subset of the IEEE 802.11e standard, which means you will get the link speed of 54 Mbps when it is disabled. It is strongly recommended to enable this function.