While it could be a firmware issue, I doubt it's the modem. The SB8200 is the modem used by Cox Business so I would assume it would be fully IPv6 compatible. OPNSense is a niche clientele though, so there probably aren't many here that can help. You might try Reddit or DSLReports. Hopefully I am wrong and someone else will chime in.
BTW, do you have any other routers you can try with? Might help to isolate some things.
Unfortunately no, no other routers available. Thanks for the response though.
I also have these events in the modem event log. When I looked them up, I found a thread from another ISP where the customer was having the issue. The company said it was because the transmission power was too high on that channel and that could cause intermittent connectivity issues. They sent out a tech who confirmed the issue, adjusted the levels, and customer reported issue was gone.
I plan on calling Cox tomorrow and asking for a Tier 2 support person as the Tier 1 person ignored my call out of high correctables and uncorrectables on channel 159.
https://imgur.com/j1uCzs9
That looks like noise or some problem with the OFDM channel. Can you post your signal levels, specifically the SNR of the OFDM channel. If possible, try uploading the screenshot directly by joining the forum using the link on the bottom found here. See here for more info. I am having problems with Imgur. It opens then goes to a blank screen. Anyone else? ::edit:: Got around it by using Firefox. Must be a Chrome issue. Feel free to use Imgur going forward.
