I cant seem to change the dungeon difficulty after completing one

[Lextragon]

When I complete heroic, I want to go another round on elite but the portal just teleports me to heroic dungeon I already completed.

[Drin]

You have to open the window and hit the reset button for the dungeon. it's [ or ] I never can remember which one. You don't need to do the one that costs Ellune you just need to click the button on the dungeon that resets it.

[Lextragon]

ok I'll give it a go