Same here on V1. I posted about this before. After this update ipv6 works about 2% of the time. Most of the time it won't provide an address, and even if it does it doesn't actually give me ipv6.

IPv4 is working? Got any public IPv4 address? For the IPv6, please share screenshots of the Ipv6 status and configuration.

Is that the upgrade changed something? I suggest you disablr IPv6 function for some time, for example 1 day, and then enable it again, to see if you can obtain the correct address.
Or you cna contact Tp-link support to see if they can help you.

Model : Archer C1200

Hardware Version : Not Clear

Firmware Version : 2.0.2 Build 20180117 rel.70858 (US)

ISP : Comcast

The beta you sent me worked quite well on Comcast. Will that be released any time soon? Has anyone in the community gotten one of the alternative firmware to work?

Never see any beta here..

Where did you get that beta? tp-link support by email?

If yes, it's better to reply him/her directly to confirm and share that with us here:)

I got it via email a few months ago and it worked well. I had to restore the router to the non beta firmware and the link I was provided for the beta firmware doesn't work. I've been trying to contact the few people in the emails I got in the beginning of the beta firmware thing and haven't heard a thing back. IPv6 worked perfectly so I hope they either test more or release it soon. I'd gladly take a link to the firmware again. :)