When opening a bank account in the EU, you get asked if you're an American fiscal resident in some sense (citizenship, US-based LLC). If you are, either they refuse you entirely, or they ask you to jump through extra hoops because they are forced to report to the American tax authority (IRS) everything about you due to American regulations.

I misunderstood your comment, you meant FATCA compliance.

But why would the US LLC need to open a non-US bank account?

Also, a US LLC wholly owned by a foreign company is a disregarded entity for income tax purposes. It is not considered a US fiscal resident.