1. A one-sentence summary of bug: 

When trying to join a Dungeon Run will say something among the lines of "Your dungeon is ready, (player name)! Do /go dungeon(number).

2. Priority to fix? {High, Medium, Low}

Medium--High, it will continue to eat dungeon keys.

3. Which server? {Spawn, Redwood, Cypress, Maple, Willow, Expanse, DungeonRun, Rush, Creative}

Spawn.

4. Steps to Reproduce: Please list the step-by-step methods to reproduce the issue

Take a dungeon key and click a button of a dungeon run with it. After loading up the dungeon, it will tell you to do /go dungeon(number), which cannot be joined.

5. Expected Outcome: What did you expect to happen?

To join a dungeon run.

6. Actual Outcome: What happened instead?

It would eat your key and not send you anywhere. 

7. Proposed Fix (Optional): Do you have a suggestion?

8. Notes (Optional): Anything else we should keep in mind in relation to this issue?

9. Screenshots (Preferred): Do you have screenshots of the problem, proof or reference?

I would include some, but then I would have to have a mod replace a dungeon key again.