Stream lag as soon as I change the game?

I have the problem that if I live stream via OBS and change the game during the stream, the whole stream (including the cam) suddenly has extreme frame drops.

But if I do a recording or something else, I don't have this problem. I'm also not shown any negative change in the bit rate on twitch.

as soon as I restart the stream or my obs, it works again without problems. I only thought about whether it is because I let the resolution downscale to 920p, but I can't really imagine that it could be.

If there are no quick solutions, I can also send pictures of my settings if necessary (if that's even possible here haha)

Do you use game recording?