Upload speed is ridiculously slow

I've tried most of the solutions that show up on the first page of google but none of them seem to work
 - restarting modem/router
 - checking coax cable

 - disabling large send offload for ipv6 (this gave me +0.2 mbps)
 - going from a Netgear n600 C3700 modem -> arris s33

Does anyone have possible solutions?