[ramzez]

every time I enable ipv6 on my pfsense, things go wrong, some sites don't open, some are very very slow to open like amazon prime or Disney plus have problems. Something is broken at router levels and until that's fixed, I keep it off

[daedalus_j]

I had similar issues (also with pfSense) during my ISP's rollout of IPv6. It seems that it was all ISP related. I turned it off and came back a few months later and it's been pretty flawless ever since. The only times it causes problems is when the ISP's v6 stack goes out, leaving us with interrupted v6 service but working v4. Doesn't seem that apps handle that situation very gracefully.

At another site I manage they have Starlink with v6 and CGNAT v4 and it's great, just plugged in the dish to the pfSense router, set up v6, and it's been ticking away happily ever since. The only problems we have are with the old devices (iot and such) that don't get V6 addresses, and have trouble with the CGNAT. (Seems like it doesn't reset long-running connections correctly perhaps, they just get stalled out. Killing the state on pfSense usually gets them working again.)

So I suspect it's more a your-mileage-may-vary situation depending on ISP than an issue with v6 or pfSense.