Why do some characters with closed counters fill in when broken apart

[markh56797949]

 

I want to create an HTML5 banner but when I publish some of the text characters that have closed counters get filled in. When I break the text up in the library they also get filled in. Why is that?

[Joseph Labrecque]

I tried to replicate this in the current production build and Animate retains all letterforms when I break apart.