my live output is video footage of a football match.

I have loaded a list of alpha channel videos loaded that I want to display over the top of the live footage.

When loaded as individual inputs there is no problem but the GPU load increases with each one - hence the list option.

When I right click and select a particular video from the list, the live output blinks just for a fraction of a second. Once selected it can play just fine - its just a problem at point of selection.

any idea what could be causing the output to blink like that?