On the WoW Armory, my guild The Einherjar on Runetotem (Alliance) shows up twice. I wonder if this is causing any of the previous issues my guild has run into (sometimes members will randomly ‘disappear’ off the guild roster and guild chat, only for their messages to be shown on the guild panel and their name as []; there was an issue also where guild finder wasn’t working for us). I opened a ticket, however was redirected here for assistance.
There are a few bugs with Guilds right now, and there’s little we can do from the forums, not sure why in-game support would direct you to the Classic Games forums for a World of Warcraft issue.
For WoW you report bugs in-game but going to Help > Bug Report, then enter a short summary of the issue. If you and your guild members can make these reports when it happens it hopefully can help us fix the problem.