See what the Analyzer thinks about your log:
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
Furthermore, one of your monitors is set to 144hz, the other one (external) to 60hz.
Set the first monitor to a common multiplier of 60, e.g. 120hz. There has to be an fractional common base between monitor refresh, readout and encoding fps.
Not to mention the hints regarding multiple capture instances...
Follow the common tips to step back one step from "Max. Quality" setting and disable "Psycho Visual Tuning"
To summarize: For alot of movement (fast game play aso.) 6000kbps isn't that much. If your connection and your computer are capable to handle, try 8000..12000 CBR and see if that works better for your purposes.