Animate stops exporting mp4 after creating nested symbol

Using version AA23.0.2 on Macbook Pro OS Catalina 10.15.7.

Whenever I create a nested symbol I can no longer export to video/media. 

I can get to the settings window but when I hit export nothing happens - no error window, nothing.

I am able to export to mp4 when I do not have any nested symbols in the file.

I am also able to export my past animations that I've made in the past with this method. 

Just to be clear,  what I mean by nested symbol is that I create an animation (for example a bee moving its wings) as a symbol then come back to the top layer and move that symbol across my stage so that I can keep my timeline from getting unwieldly. 

I've been creating short animations (no more than ten seconds long) to post on Instagram for about a month or so and this has never happened before. To explain my workflow a bit more, I create my illustrations on Illustrator and import them to Animate. 

A solution would be much appreciated. Thanks.