Home internet keeps disconnecting

Is this with a WiFi connection ? If so, as a test, does a computer / device that is hardwired directly to the router / gateway device with an ethernet cable have the same problem ?

With this test, we are trying to isolate this down to being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step in troubleshooting before proceeding any further. 

Hello and welcome to Comcast! I want to thank you for giving us this new opportunity to work with and your family for all of your entertainment needs! I am sorry to hear that you are having troubles wit you service.

Please send us a direct chat message with your full name and complete service address to “Xfinity Support”. To do so, click on the chat icon located at the top right of this forums page.
Here's the detailed steps to direct message us: 
 • Click "Sign In" if necessary
 • Click the "Direct Message” icon (upper right corner of this page)
 • Click the "New message" (pencil and paper) icon
 • Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
 • Type your message in the text area near the bottom of the window
 • Press Enter to send your message

Let me know if you have any questions.

@user_yj6kq6 

Have you had a chance to try that test ? Please respond right here in your topic on these public help forums. Thank you.