Just to chime in: After years of enjoying Plex remotely, my ISP has decided no more free IPv4 addresses and has switched on DS-Lite (before a call was enough to get it switched back to IPv4, but now they want to be payed extra). Using the relay is no fun and unnecessary too. With one of the workarounds sketched here ([SOLVED] Secure Remote Access with IPv6 Dual Stack Lite (no public IPv4)) I was able to get it to work, but only for a couple of hours until my IPv6 prefix changed (it does so every night, same as my IPv4 address used to).
Obviously this request gets my vote!