capture card flickering

Never had a problem with this before but for some reason out of nowhere when I play Minecraft the screen on obs is flickering and even the video is flickering. I'm still trying to find a solution but still got none. I need help.

Hello. I wanted to record some footage from my Sega Master System, but when I got everything setup, the preview footage (as well as the actual footage) was flickering in & out. I am using a generic composite capture card since most old ones like Dazzle arent supported on Windows anymore. If i...