When you push a scope, you have an isolated scope from others but that scope inherits all values from where it was forked from (the place before you called push). Once you exit the using block all crumbs and tags you set within that scope will be lost. So an event captured after that point will not include them.
Could you confirm you are only seeing crumbs that happen before the request started (such as ‘app started’)?
How are you initializing the SDK?