Internet unstable

OK, so my connection for while has been super unstable. its been going on for 3 months and the problem hasn't got away. My connection would out of nowhere stop and then continue again. I've already tried to restart my modem even tho just a few days ago I upgraded to the gigablast connection and I have had cox doing troubleshoots which would fix it for a bit but it would just start all over again. Also when it disconnects it would show that IPv6 is disconnect and rarely it would also show that IPv4 is not connected. I would really like to know what's happening because I can't go on for 5 minutes without the internet just disconnecting for 2-10 seconds. My desktop is also connected via ethernet cable and the rest are wireless.