難点 なんてん
nanten

Noun

1. fault; weakness; flaw; defect; drawback; disadvantage

あそこの ものはうまいし値段 ねだん やすいが、地 わるいのが難点 なんてんだね。
asokono tabemonowa umaishi nedammo yasuiga chinoriga warui noga nantendane.
That place's food is great, and their prices are good, but the fly in the ointment is their terrible location.
Noun

2. crux (of a matter); difficult point; point of contention

ただし 瞬間 しゅんかん気圧 きあつ変化 へんかのせいでしょうか、耳 みみがツンとするのが難点 なんてんです。
tadashi oshikomu shunkan kiatsuno henkano seideshōka mimiga tsunto suru noga nantendesu.
However, maybe from the sudden change in pressure when you push them in, having your ears pop is a problem.