Windows 10 v1709 (Build 16299.125)
Tixati v2.56 x64 portable: Settings > Behavior > Notifications > Configure... > Tray balloon click action > set to "Show Transfers".  

Scenario: With any other application open or even with only the Windows desktop up, when a download completes, click on the notification balloon.  It attempts to switch to the Tixati transfer window, but it doesn't.  I see the Tixati taskbar item flashing orange, which means it's trying to, but it's stuck in the background.  Of course I can manually click on Tixiat taskbar item, but that defeats the purpose of this setting.  I think this used to work in previous Windows 10 versions?

As a test, I changed the Notification behavior to "Open Folder" and this setting works fine.

It seems the problem is not specific to Tixati's show transfers as it also happens when launching Tixati by opening .torrent files too.  It only happens when the other active application's window is in a maximized state.  Probably Windows 10 problem >:(