@plzhelpmesir I would backup the router and start changing settings and reboot or power cycle between changes. I would change the IPv6 settings, the homeshield settings, firewall settings, advance...

@Cat7 Also be sure you did not press the WIFI / WPS button on the router.

@Zebra789 Most just use router mode. AP mode is used when you connect the router to another router or to a gateway (combo router modem).

@-haering_360 If you are using QoS, turn it off. Do not use a VPN. Use separate WIFI addresses. I would recheck the Xfinity lines and connections. Are they also providing cable TV? If so, check those...

@Bluesters I would try with the QoS off. Also would try adding a cable between the Stick and TV to change the location a bit as you may be getting interference.

@thomasjefferson First thing I would do isto connect the computer direct to the modem and run some speed tests. That will give you a clue to what to check next.