Setting a Theme on an Application breaks the Localization on the Userflow

We have multiple Custom Branding Themes for our different Entra Applications.

On our User Flow we have a couple of labels overridden. The language overrides in the Userflow work, as long as the Application that I start the Userflow in has no Theme applied.

I tried setting the Labels in the Theme and Theme Languages, but it always shows the default labels.