High Correctables/Uncorrectables + IPv6 Drops About Once a Week + Serious Lag - Time Warner Internet

This question is about "High Correctables/Uncorrectables + IPv6 Drops About Once a Week + Serious Lag", with Time Warner Cable internet and apps. Hello,

Every 5-7 days or so, my router loses its ipv6 address (according to the »test-ipv6.com site). Around the same time, I start seeing a lot more correctables/uncorrectables on Channel 8, with all other channels remaining at 0/0 (no errors).

I'm not sure if these two things are connected, but they both happen at least once a week. It takes 2-4 days at least after a reset to start seeing errors again.

As far as actual usability symptoms, I start seeing a lot of lag when browsing the web. At first I thought I had some sort of DNS lookup problem.
The other major symptom is that YouTube starts skipping and stuttering, and no longer defaults to 1080p HD (usually it ends up between 360p/720p depending on what the video has available).

The YouTube thing is less of a serious problem than it is an indicator I need to reboot the router.

Today, I had to reboot the router twice in a row to get the v6 IP back.

I have attached a couple of time-stamped screen caps of the status screen from the Charter box.

As far as outside interference, I do not believe it's anyone's cell phone in my apartment. Cell phone use patterns are pretty much the same every day (a combination of wifi calling/data and 4G on AT&T Wireless), and it takes 2-4 days before any issues start. And even then, after I start seeing errors, they stay very low for a day or two before they balloon and I have to reboot the router.

I originally signed up for cable TV service with set top boxes, but cancelled that service. I think there might be splitters in my apartment, but I'm not sure. The only service I still have is internet, so I only need the one cable running from ... Wherever it comes into my apartment ... To the wall jack, to the cable modem.

Here is a screenshot of the status page:

High Correctables/Uncorrectables + IPv6 Drops About Once a Week + Serious Lag?