As you can see in the screenshot above, the ATT window is quite large. I was messing around with it a few days ago and once I expanded the window (by dragging the bottom left corner outwards) it wouldn't allow me to interact with it anymore.

I've tried refreshing, logging out, deleting the addon and reinstalling, and none of these have worked. I love this addon and I can't use it right now because it's super painful to look at with how huge it is in the top left of my monitor.

If you cursor over the header of that window it probably shows in the tooltip that it has been Locked and you need to Alt - Click the header to unlock the window. For example, any locked ATT window should show this in the tooltip on the header for the respective window:

Gonna go ahead an assume you figured this one out :)