Even though you've done it, "This is a repeatable quest that you have never completed."

[Guidorocker]

"This is a repeatable quest that you have never completed."... It says this even after you complete that exact same quest!
o.O

[DoRonRon]

Possibly one of these re-versioned quests?

[cdq1958]

There are some repeatable quests that are essentially placeholders. You complete them but completion is not saved because they need to use that quest placeholder again. Fortunately, there are not that many of them. That said, it is confusing if you don't consider what may be happening on the server side database.

[MandravalGalabian]

there might also be two (internally) different quests, that have the same name.

sometimes there is an introduction quest, and a repeatable quest, both named the same...

I know, that there are two different VIP-quests for the townservices...
the first one, you will get, if you did not complete the moria-introduction (and then the town services will have the forge-master missing)
the second one, after you have access to legendary items, will be full service.

so, when you repeatedly have done the (lower-level) VIP quest, the first time you accept it, after you finished moria introduction, the quest will be marked as "never been done before".

[maartena]

In some cases, the first time you do a quest it isn't a repeatable quest YET.... it is a regular quest that is needed to be done for the quest progress in that zone, but once you have done it once it BECOMES a repeatable quest from that point forward. If that happens, you often can do the repeatable version of the quest right after the "normal" version of the quest has been completed and you can move on in quest progression.

Can't think of an example of the top of my head, but I think the Aiding the Elves quests I, II, III and IV in Lothlorien are setup that way. Once you have delivered those arrows on quest I, you can do it again as it now has become a repeatable. After that, it should be a once-daily repeatable only.