in your log i do not see any screen recordings and only a decklink recording. :
10:30:36.445: Loaded scenes:
10:30:36.445: - scene 'Scene':
10:30:36.445: - source: 'Blackmagic Device' (decklink-input)
10:30:36.445: - scene 'Scene 2':
10:30:36.445: - source: 'Blackmagic Device 2' (decklink-input)
do you have tried desktop video setup, if the blackmagic software is able to work with your hdmi splitter?
10:30:35.366: output 0: pos={0, 0}, size={1920, 1080}, attached=true, refresh=144, name=
10:30:35.366: output 1: pos={1920, 0}, size={1920, 1080}, attached=true, refresh=60, name=HDMI SPLITTER
i think you are not doing a direct screen recording, but you record your display via a hdmi splitter. is the splitter powered on ?