Weird UI element. Pet display?

[Faxi]

Just returned to server. There is a square, blank, UI element - not a chat window - that cant be closed. Right click says Pet Display. but my pet window is already open. How can i close this window? thanks

https://flic.kr/p/2pV9L3u

[Kavious]

That looks like a Group window. Have you joined any groups since returning?

Alt-P should toggle this on and off

[Faxi]

That looks like a Group window. Have you joined any groups since returning?

Alt-P should toggle this on and off

ya haha i realized that about 10 secs after i posted this. it being solid black confused me off. cheers