Hi all, for an unknown reason some/all of the Vmix clips and prev/pgm monitors go blank at random times soon after I load preset.

After rebooting or quit/relaunch VMix it comes good, then if I go into vmix settings, a clip settings or just wait a min, some/all monitors go blank again.

This is using a (work) Surface Pro 4 laptop with 8gb mem. Has been working perfectly fine for a couple years.
Vmix display at Pal 25fps 1080p. High Performance mode checked or uncheck makes no dif. VMix shows CPU 3% GPU 2%.

Any ideas would be most helpful.