Look at the top entry in the log. T3 timeout. Every time a T3 timeout occurs, you will have major packet loss and you often will have some packet loss between T3 timeouts as well. Because of the way the modem logs work, you might see "only one" T3 timeout, but if you refresh that page you'll probably notice that the time of the T3 timeout is changing. This is because the modem only shows the most recent entry for each event type if more than one event occurs in a row.
Keep watching the logs and see if the T3 timeouts continue. Even if you see "only one" check the time and see if it's changed. No amount of Microsoft troubleshooting will resolve a T3 timeout. Because your downstream looks good, this issue could be caused by upstream noise ingress which is a very common problem on the cable network.
If you see more T3 timeouts occurring (remember, check the time, don't just look at it and say "it's only one") you need a Cox tech to check out the equipment in your neighborhood. If your on-premises equipment had problems it would be very likely for you to be seeing downstream uncorrectable errors or T4 timeouts.
Would that be my main issue from what you can tell? Its worth noting that one tech deemed my aerial line as bad and said it was at least 10+ years old and from before Cox switched to digital. The next 3 techs said he was wrong and that didnt get replaced
It might not be the only issue, but you need to get it fixed before you start changing or replacing other things. As long as you are experiencing T3 timeouts you will have packet loss. Note that T3 timeouts are not the cause of the packet loss. It's an indication of packet loss that is occurring due to problems in the RF network.
