Fresh Install / Build : After 15 mins drops to 1FPS etc

After a few mins of running with a game operating, XSplit tanks to 1FPS and stutters and fails.

Brand new Windows 10 Install 2-3 days ago, on new 1TB EVO 980 NVMe SSD, All Windows Updates completed, latest drivers installed for all software and hardware.

No Streaming, NO Recording just trying to operate idle with XSplit operating at the ready.

It starts normal but after 15 mins of normal game play with XSplit just idle it performs at 1FPS becomes choppy and broken.

Dual Screens so no excessive load there, 1 x main monitor and a 1080p Portrait mounted secondary.

GPU goes to 99% then Xsplit slowly implodes in on its-self, as you can see its not a crap GPU so what possible explanation could explain this anyone?

XS1_ Running Game Round 5 start xs (2) !