There is a bug. When you go to Membership->All Members -> hover member and choose "Subscription Details" -> History and logs -> Status (check and update subscription status)
refresh icon -> so far so good. CLOSE subscription Details" popup window -> CLOSE last window -> when you close last window, all dark and inactive background stays, as it should to dissapear.
I want you to know, so you could fix it, as it is not so big problem, just every time now I need to refresh page so it would work (after I check this history).