Noob rendering - original bitmap image remains behind animation(Solved)

I’m a raw noob to Synfig, so please forgive me if I’m missing something obvious.
I’m making an animation from pngs with skeleton deformation. When I render the animation, the original still remains, with the animation happening in front of it.
Can anyone tell me how to rectify? Thanks in advance.

Hi and welcome! Could you post an example, so that we can have a clear picture of the issue?

WholeoctoAnimated
Even stranger, the error is corrected as displayed here but when I run it on my PC, there’s a fault as I’ve described.

So the problem is with the rendered GIF?

Sounds like the problem has to do with the PC; as stated it’s being displayed correctly here

It displays differently, depending what you view it in.
I’m calling it solved, thank you both for your replies