BUG: App Extension for 404 template doesnt always load

[JoshHighland]

I have an app that uses the 404 template in the theme app extension to record 404 hits

From testing I have found what I believe to be a bug. The theme app extensions only run if the 404 page is triggered when referencing a known object type

Example:

Theme app extensions load:
domain.com/products/missing-product

Theme app extensions NOT loading:
domain.com/missing-page

The contents of the 404 template load, but the theme app extensions do not