There is no black screen with other panel. It simple detects only 1 panel which is selected as main monitor. I have tried all advises here from forum including. I have also selected preferred graphic adapter the integrated one, but still does not help. What is funny that previous product OBS detects both monitors. The OBS Studio does not, and I believe it supposed to be newer and better. I would say this is something which needs to be fixed on program level rather than asking users doing this or that and for some people it works, and for some it does not but perhaps I want too much from the project is is based on free open license. I don't know what else should I try. Thanks anyway.