Please check the analizer and look at the recommendations/fixes for some common issues.
OBS (Open Broadcaster Software) is free and open source software for video recording and live streaming. Stream to Twitch, YouTube and many other providers or record your own videos with high quality H264 / AAC encoding.
obsproject.com
In OBS audio settings (at the top) set the sample rate to 48Khz.
It is recommended also to enable windows game mode.
1) Restart OBS.
2) Start your stream/recording for about 30 seconds. Make sure you replicate any issues as best you can, which means having any games/apps open and captured, etc.
3) Stop your stream/recording.
4) Select Help > Log Files > Upload Current Log File. Send that link via this troubleshooting tool or whichever support chat you are using.
If it keeps happening, lower those kbps to 3000 and go up until it start giving troubles.
And to test your Internet connection against Twitch it's adviced to use
Twitch Bandwith Test. Please make a screenshot of it and post it here. Test it only for your region.