I've had this problem ever since El Capitan I think.
When switching betweenEyeTV 3 and other apps (usually using a Logitech universal remote and Remote Buddy software to trigger app switching), about half the time EyeTV will only show a black screen or sometimes what looks like a paused TV channel. The strange thing is I can hear the audio of the TV channel still playing in the background. Changing channels doesn't help, I still only get a blank screen or paused frame, even though now I can hear the audio from the next channel I've switched to!
The only way to get out of this is to close that LiveTV window and open another one - or to switch between TV tuners (I have the Diversity).
I've tried just about every setting and arrangement I can think of, but can't seem to get EyeTV to behave itself. The weird thing is about 20% of the time it behaves properly.
Anyone have any similar issues or have any suggestions as to what might be causing this?