Stream not showing Optifine Minecraft?

I recently started streaming Minecraft and wanted to play it with Optifine. So I shared my screen at Twitch Studios (like I always do) and started Optifine Minecraft. The picture suddenly hung in the stream, although everything was fine in the program itself. Why is this and how can I fix it?

The screen recorder can't record full screen.

You should use OBS for this and stream that with it.

Why not with OBS? Programs made by or for Twitch are not the best choice.