No, I think you have the right number

That's just what they want you to think. < _<

If the recipient was an old number that was re-used.... or you didn't put the number in the contacts right. That'd imply this is the first few texts sent... which is it's own story.

Old numbers being reused is something very uncommon in Germany, maybe that's an explanation.

Perhaps... ya'll got 11 digits, right? It's 10 here after a "1", meaning 10 digits. So ya'll are literally on another magnitude.
minus 555's.