Ethernet problém

[KrisyKris]

So today i just finished playing around with my old router wanting to make a switch out of it for my 2 pc's and after a day of fiddling i managed to hook Up a long ethernet cable from the main router into the old configured router in my room to which i then connected 2 more ethernet cables for the pc's, it all runs well as it should but sometimes i lose connection on my phone saying "connected, no internet", and i have to disconnect the long Ethernet cable, and tips?

[RageTester]

If wifi is the problem, get a directional antenna. I don't see how unplugging ethernet cable can fix wifi unless you are maxing out the bandwidth provided by your ISP... You can experiment with DHCP server on/off on the old router.

[KrisyKris]

I guess it must be the bandwith, because our tv is connected to the router too, (see photo) and we experienced stutters when everything was connected, and i turned off DHCP on the old router so it wont conflict with the main router, but i will look at it again, thanks for the explanation.