n64 screen shows gray on my crt help

can somone help me fix this analog horror type shit, it only happens with the n64 that i use but not with the gc and the snes, also the gc and snes are both european and the n64 is japanese w the region unlock do could be that i need a different scart cable? idk somone help me i just wanna play sm64 and pm, also on my monitor it doesn't do that but i think it's because i have a hdmi converter for when i speedrun the games so i can stream ro the pc, i don't really know lol.