Single-spa ValueConverter not found

Hey .

I use single-spa with Aurelia and have problems with the ValueConverter there.
The Aurelia applications are built as SystemJs modules and displayed via single-spa. Two applications are never displayed at the same time. So in the DOM only one Aurelia application is active. So far everything works.
Application A uses a Value Converter, application B has none.
If I switch from application A to application B and then back to application A, the value converters used in application A are searched in the code of application B. In the html, the binding is not resolved at the corresponding position and the variables are visible. The Error Message is ncp-produktliste.js:2 Uncaught (in promise) Error: No ValueConverter named "currency" was found! (produktliste.js = application B)
If I include the same ValueConverter in application B, it has no effect, the same error happens.
Does anyone have an idea what this could be?
(What is also strange: click.delegate is triggered 2x at buttons, click.trigger only 1x).