About once every 2 to 4 weeks Comcast does something that causes my router to lock out my phones and tablets but not my PCs. Unplugging the router for 15 to 30 seconds and powering back on fixes the issue every time. Comcast always says they have done nothing but using several routers of different models and makes makes no difference with Comcast internet. They all have to be powered down and back up to allow my Android devices to connect.