Hmmm, no I just tried and I don't have that problem. For me, Rusev is the US champ. So I went to customize a match, picked one on one, and then Selected Rusev. It then asks if I want 0, 1, 2, 3, or 4 managers.
I was able to select 1, and picked Lana and then selected Reigns as the challenger. At that point I went to Match Details and made it a US title match
EDIT: Actually, I went to actually go play the match and it wasn't there...so yeah, there's a glitch there. It won't create the match. It works without a manager though. Very frustrating.