Account switching vs. parallel account display

[Eldorado 26]

I use different evernote accounts in parallel (2xPremium and 1xBusiness). Normally I can switch between the account by typing Ctrl-Alt-A. Since some days (after added the Business account and installing newer versions (6.8.x and 6.9.7)) Ctrl-Alt-A does not switch between the accounts. Now it displays two accounts in parallel in two windows. Might be fine for some people but makes me crazy because it is very hard keep track of the assignment of specific notes to accounts.

Two questions:

• Is this a "feature" of using Business or the new version?
• Is it possible to deactivite this? I want to have only one account be active at any time (like in good old times ;-)