Not sure what specifically happened in your case, but FWIW... My ISP (Spectrum, previously Time Warner) has supported IPv6 at my location for a decade or more now. And I have been running with IPv6 enabled on my router, and on all my Linux boxen, and have had approximately zero problems related to IPv6 in that time. During that time I've had boxes running various Fedora versions, and PopOS and both have handled IPv6 just fine.