Thanks for the input, I first was considering that LH only knows about what they need to - but I found it odd that I haven't found anybody else who posted that problem/effect. What about the missing ticket number? Does that indicate that US might not have issued it properly like I've read somewhere?

I really don't trust US IT at all, I didn't receive an email confirmation (only after I called) and it seems like the booking put my online account into error mode where nothing besides logging in works. Can't view my miles, change my details etc. But I guess that's going a bit offtopic for this forum now.