My upload speed has been abysmal for a couple months, I think since IPv6 rolled out in my area. I have an SB6141 and a Netgear R7000 router and I consistently see Xfinity speed tests like this:
Ping Down Up
IPv4 14 ms 59.00 Mbps 0.30 Mbps
IPv6 12 ms 58.51 Mbps 11.50 Mbps
Anybody know what might be going on? Thanks for your help.