Can't Start the Next Waygate Quest

While unlocking a Dragonflight Expedition waygate allows all eligible characters on the account to use that waygate, unlocking waygates across the Dragon Isles requires both obtaining the prerequisite Dragonflight Expedition renown and completing the initial questline on the same character. If you completed the initial questline on a different character, you will have to do it again on any other characters to receive the additional quest.