There are still a lot of issues with keyboard focus. And I cannot get my head around it, as it seems to be very random.
When opening a plugin, could be a UAD insert effect, or a VST like Superior Drummer 3, S1 does not always hand over keyboard focus to the plugin. So I open a LA1176 from UAD, click on the preset dropdown, and pres arrow down, or I open the grid editor in Superior, select some notes and try moving them with the arrow key... in stead of action happening in the plugin, S1 is selecting a different track in they arranger and closing my VST.
It does not happen every time, but when it happens, I am unable to get focus the the VST in any way. The expected way for keyboard focus is that it's redirected to the active window. When I click on the S1 main window and then on the plugin window, I see that the focus highlite in S1 disappears, but it is not moved to the plugin.
It makes using plugins like virtual instrument that use keyboard shortcuts totally impossible. Please fix this. If it'a difficult to decide which plugin does or doesn't need focus, then please make it a toggle option on the plugin so we can force keyboard focus to the plugin when the GUI is open.