I am afraid changing the culture is not going to take an effect at runtime.
I can suggest you a bit different approach, which I hope is going to work for you. You can find a demo solution attached.
The steps to perform are as follows:
1. Run the attached solution
2. Set the current culture (by pressing the "Set English Culture" or "Set German Culture"
3. Click on the "Set Language on Culture and Rebind"
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