Runs great....then goes CPU nuts

I am running OBS 2.8 on a Surface 6 Pro (spec if needed)
I am running 1080/60/6000 and streaming to Facebook and YouTube with the obs-multi-rtmp plugin

The interesting thing is, It runs great with 5-7to9 % CPU with those settings for about 10 minutes.Then all of a sudden it runs up to 18-20% and dropping packets and dropping frame rate. Has anyone else seen this and what should I be looking for in the logs? Any guidance would be appreciated.
 
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