Hey gang,
Just found this thread after hours upon hours of attempts at fixing this. I, too, am experiencing loading screen lag when recording from my Elgato HD (the old one) through OBS with HDMI. Whenever I hit a load screen, a fade to black, a fade from black, a menu transition.... I get 1-3 seconds of audio/video lag. The video freezes, audio cuts out, and then moments later it all smooths itself out.
tl;dr, same issue as everybody here.
I've yet to try downgrading the driver software (will do that momentarily) but a fix for this is absolutely necessary.
ABSOLUTELY NECESSARY.
I will provide the log files for my current set-up. Please note, that I've attempted multiple different changes to OBS and Elgato settings, as many others have; recording/stream quality, bitrate, FPS, resolution, encoder.... Nothing has solved this problem.
Keep fightin' the good fight, folks. They can't keep us in the dark forever.
Log files below. Pastebin due to thread character limit.
http://pastebin.com/aWaGW43K