Extreme framedrops when streaming?

Moin as in the title I have extreme frame drops when streaming…
I'm currently streaming via Streamlabs OBS, but I also streamed via the normal Obs, so it's similar… The program runs on my 2nd monitor
As soon as the program starts and the stream is running, I logically don't have as much FPS as before… It's already clear

without stream I have in Fortnite low 200 and high 280 frames approx
with stream low 60-85 and high 230 through the 60-85 low it appears as if it were extremely jerky. As soon as I minimize the streaming program, the problem is gone! So don't close just minimize it. Although the stream then continues…
Hardware:
Ryzen 5 2600 OC 4.2 GHz
RX 580 8gb
Gskill Aegis 3000mghz 16gb
if you have any further questions ask…

Times deactivate the preview

do you render over cpu or gpu?

Currently GPU because I don't want to load the CPU so I play fortnite on low one way or the other and CPU is more important for high frame rates… But it's not better via the CPU either… How can I switch off the preview on streamlabs?

Right click on the preview and deactivate

Streaming with this CPU is not advisable because it only has 6 cores and the CPU usage is higher than the graphics card usage. However, the AMD decoder is no better either.

Take a look at the tutorial on youtube how the correct settings are.

Don't need any tutorials just used the normal obs beforehand there was the same problem… It must be something else… Otherwise it would be because of the streaming itself and not because the window is not minimized

This is this preview that eats up extremely performance

I'm just testing it

Was the preview thank you.