Win10 fullscreen: OSX menu/dock/smart corners active, cannot click to activate Win again

Hello everybody!

I'm using Parallels 12.1.0, Mac OS El Capitan on a Mid-2015 Retina Mac Book.
Input devices: Trackpad (seldom used) and Logitec wireless mouse (mostly used)

Now a serious issue appeared: using Windows 10 in full screen mode works fine so far, but when I move the mouse pointer to the top edge the OS X menu bar appears while at the bottom there is the OS X dock.

Worse still when I go to the top left corner the screen selection appears as is configured in OS X.
After that I'm locked out, every time I click on the Windows screen to get there the system behaves as if the mouse pointer is in the left corner and shows the available screens again.
The only way out is to make Windows windowed (leave fullscreen) and then go fullscreen again.

I'm using Windows mainly for games and this behavior is at least annoying...

My settings are (roughly translated from the german version):
General: optimize for games
Options: Full screen: optimize for games (so the problems mentioned above should NOT occur...)
Hardware: Graphics: optimize for external monitors (for 2880x1800 pixels is a little bit too tough for games on my Mac - every other setting behaves the same way, though
Mouse & Keyboard: each optimize for games

I don't know if this is a real bug or just some wrong settings ... This bug appeared the first time today after I finally registered my copy of Windows (and made it configurable, so maybe this comes from the Windows side?)

I'm totally clueless - yesterday normal behavior, must Ctrl-Alt to leave Windows mouse control to get OS X menu, dock and screen selection, now this :-(

Any help would be very, very appreciated...

Thanks in advance,
Thomas

 

Update: Playing with the mouse settings (auto detect mouse for gaming) the lockout and the dock/menu bar issue seems to be solved.

Strange though, the active corners from OS X are still working, screen selection (upper left) and Launchpad (bottom right) ... still annoying while fighting in games and not what I'm expecting.