Apex won't always close on steam

Whenever I close Apex, Steam still gives me the option to close it, and when I do, it's stuck on the stopping greyed-out button. Sometimes, if I close Steam completely, it will close, but sometimes it just doesn't. Also, I cannot find it on Task Manager, but I can see it on Process Explorer, but I get an access denied when I try to close it through it. Any help would be appreciated.