Can't use Library Editor - stuck on last component

I know this is going to be one of those questions I shouldn’t have asked…but I’ve been trying to figure out for well over an hour now how to do one simple thing…

Close a component I have open for editing in the Library Editor…and open a different component.

I’ve tried everything…nothing makes sense.

Every time I reopen the Library Editor, the same component reopens.

Help!

Thanks so much. Couldn’t find that if my life had depended on it.