How does my Twitch Stream run more smoothly?

I stream via OBS Streamlabs, but unfortunately the stream rarely runs smoothly. Today I finally have time to set it all right, but unfortunately I don't even know which settings are relevant xD

Note: It has to be the settings, because streams on YouTube run much more smoothly.

If you have any questions about my settings, I will of course try to provide information, but please also provide the path in the program (if you know it)

Otherwise, thanks for the help and stay healthy ^^

Bit rate, upload and resolution are very important.

So the video bitrate is just 3500, audio 128

Unfortunately I do not know whether the video resolution = the stream resolution, but it is currently at 1280 * 720 at 48FPS and according to the speed test I have about 9MB upload

You should turn up the bit rate until it lies. Try it first with 10k