In-game help/customer support window not working

I’m trying to use item recovery in-game, and I’m told I need to go through the Menu → Help → Open a Ticket screen to do that. The problem is that my “Open a Ticket” button in the help screen just displays a blank window with a black textured background, with a yellow progress indicator at the top going in a perpetual circle even after several minutes. Same for “Knowledge Base”, though all the other side buttons work. The “Go to the home page” button also does nothing, and hitting “Stop” makes no visible difference.

I’ve tried disabling all add-ons and it doesn’t help. I’ve also tried clearing the cache and deleting cookies from the settings button in the upper right, and neither helps either.

My game seems to be working fine other than this. Can anyone help?

Edit: I’ve since tried the steps in this article to completely reset my WoW user interface:

That fixed the problem. So apparently, whatever was causing the issue, disabling all add-ons alone wasn’t enough.

Also, as it turns out the in-game system just sent me to https://us.battle.net/support/en/restoration on the web for item restoration, so I didn’t even need it to be working at all.