Xbox One disconnects from time to time help

Rebooting your router by unplugging/ turning it off for 30 seconds usually fixes that problem, its not a fault with your xbox its a connection error.

Is the first device also a router ? 4 ports on the back ? if yes , try hooking the Xbox to it and see how it does....

If your other devices still connect to the Internet fine, I suspect there are firewall/port settings that are blocking your Xbox from accessing Xbox Live. You will have to access your router settings, so open up a separate browser window on a desktop/laptop
computer.

UPnP on your router doesn't appear to be doing its job properly, so you're probably going to have to manually open ports for your Xbox.

Here are some (generated) step-by-step directions to open ports on your D-Link router: http://portforward.com/english/routers/port_forwarding/Dlink/DMG-6661/Xbox_One.htm

Here is the
official port list on Xbox's support article for the ports you need opened, as I think that the link above doesn't do them all. I'd cross-check just to be sure. Don't worry, they can be input in any order.

This may take some time, so please have some patience as you go along.

Hope this helps!

Tried that right now, I has able to navigate using my smartphone over the wifi, and none of the LEDs on router turned red or showing something different ... I was wondering if there is any tool I can download to keep track of my internet to see if it when
it disconnects me something happens on PC too or just on Console cause as far as I can see the PC is fine until now

Nope, one is the router and the other one the modem, Modem does not have 4 ports on the back only the Router does!

Any chance the problem is with my Xbox? Its the Day One Model btw idk if it helps somehow...