Garry's mod has become "Unbought" after updating to new steam UI

Hello, after hearing about the new Steam UI I quickly downloaded it. Now I want to play some Garry’s Mod.

When I opened it in the games menu, the background was red. When clicking Play Game it re-directed me to the store page. I have just tried restarting Steam now. But I still have the problem.

Have you tried switching back to the normal Steam? If it’s unbought there come back, if it’s not it’s obviously a ui error in the new beta

Says it’s 100% Ready. Should work now. Thanks for the help.