I don't see anything on LH's website about them flying to AUH. The route map shows DBX, but no AUH. And when I start to type AUH (or Abu Dhabi) in the destination to look at flight options, Abuja International (ABV) is the only option that it populates the form with. Maybe they've stopped their service to AUH?

Actually, doing a search online, it appears they stopped the FRA-AUH service last summer. That would have been a great option otherwise!