Disable your addons and check again.
If not do a UI reset by moving your WTF/Cache/INterface folders and letting the game make new ones. You can move the old folders back after if you want.
If you did the full on UI reset, and you're sure that you placed gems in them, you're probably going to have to open a ticket and ask a GM to look into it for you. I don't know if or how their logs will show anything, but it would be your only option at this point.
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Threats of violence. We take these seriously and will alert the proper authorities.
Posts containing personal information about other players. This includes physical addresses, e-mail addresses, phone numbers, and inappropriate photos and/or videos.
Harassing or discriminatory language. This will not be tolerated.