IPv6 issues on browser

Hey guys!

I am using OpenWRT 22.03-rc6 on a Asus RT-AC58U device. My ISP provides a /64 address.
I am getting IPv6 address for my devices, and I can ping using v6. But I cannot access IPv6 sites using any browser. Doing an IPv6 test says, that I do not have IPv6.
IPv6 previously used to work with the default setup on the stable and rc builds. The only thing that has changed, is that the ISP replaced my ONT with a new device.
Please help me with this!

Thanks

Edit: I tried using the stable build, but the issue persists

Bump. Anyone?

Is your client device a Linux? Check /etc/resolve.conf and systemd-resolved --status
Then Check nslookup google.com and see which nameserver is used and if you do get a response with an AAAA record

Well, I am able to ping google.com over v6. So the DNS is obviously working and returning an AAAA record. It is everything else except ping that fails.
Also, the OS is windows

Bump. Anyone?