Theme not properly working on expiration of site

I have a free site level theme that and non free sites that include multiple themes. If a non-free site payment source fails to bill it will go back to the free level which only includes the one theme available to all themes.

This theme works when a person signs up for a free site. However when the site expires it will show that it goes to the free theme...however even though it is selected in theme I noticed that the the theme isn't actually activated properly. So when the a person attempts to view their site it will show blank.

Any ideas why this is occurring?

Thanks!