Nested Animations Disappearing at the End of HTML5 Animations

So I'm relatively new to Animate and am unfortunately working with a tight deadline. I nested two more minor animations into symbols to scale them proportionally into different google ad sizes. Unfortunately when I output the file the HTML5 and run them through the validator, those two symbols blip out at the end of the animation. I can't seem to find why this is happening, all I can speculate is that it has to do with the fact they were nested.

Unfortunately, I can't post screenshots due to legalities.

TIA.