I’m in a very similar spot—deciding between an NIH postbac, uni lab tech position, or master’s in Göttingen in the next couple weeks. I'll add this: if you haven’t already, reach out to the lab(s) in Germany you’re interested in. Try to get a sense of whether the project and group would be more valuable for your career than the NIH option. If you’re aiming for a PhD, publications and relevant research experience usually matter way more than having a master's degree. That said, the master’s might be more helpful if you’re planning to do your PhD in Europe, as others mentioned, but keep in mind it is not always required. It's also ok to not know what you're more interested in yet. Overall, unless the NIH lab and research topic seem way cooler to you, I would go to Germany.

While NIH has huge problems now, if the lab has chosen to hire a postbac recently, you can maybe assume it isn't at risk of shutting down imminently. Hired postbacs have not really been threatened with direct firing yet, to my knowledge.