No word on getting this fixed or how to fix it? 

@pontpontf Honestly it is happening on my Archer AX6000 too.  It works for a few days to a week and then the DNS routing gets messed up and sometimes I can't load the router's management page.  When I disable IPv6 I have zero issues with the router.  Unfortunately I don't have advice on how to fix it but I am planning on reaching out to my ISP to get proper settings and then test again.  If that doesn't resolve the issue I'll reach out to TP-Link for clarification but IDK if they know of the issue.

pontpontf wrote

IPV6 is not working on my router. I enabled it, and in the router cp it looks like it's working, but it isn't. If I plug any device directly into the modem, IPV6 works immediatley, what's going on with this? Thanks,

 

https://forums.xfinity.com/t5/Your-Home-Network/Comcast-IPv6-Not-Working/td-p/3034722

 

According to this it is apparantley a problem with this specific router. Now I have to buy a new router since apparantley tp-link has no interest in fixing whatever it is they broke with a firmware update several years ago. Yet it's still avaliable to purchase, gotta say I am seriously not impressed with tp-link and and will never make the mistake of wasting my money and time by purchasing any of their products again,