PNG on an animated path disappear while rendering

Hi, three masked PNGs on an animated path keeps disappearing while i render my video and I cant figure out why.
I am trying to get the images to float around on the screen along different paths and they appear to be fine in the timeline and in fusion, letting me alter the path and keyframes without problems It is previewing exactly as I want it but when the video renders they disappear, no sign of them in the final result.

When I go back to the timeline after a rendition they no longer function or appear in the preview but they still appear in fusion.

Any idea what I could be doing wrong?

Thanks in advance.

[Peter Chamberlain]

8GB ram is really to small, particularly for Fusion in Resolve. We recommend 32GB min.
try rendering just that clip and then put it back into the timeline.