Passing by each other (while moving in opposite directions); the act of passing someone or something.
狭い路地で自転車とすれ違いになった。
I passed by a bicycle in a narrow alley.
駅の改札で多くの人とすれ違いながら歩いた。
I walked through the station gate, passing many people.
Missing each other (failing to meet) because schedules don't match; failing to rendezvous.
予定がずれてしまって、結局すれ違いになった。
Our schedules shifted and in the end we missed each other.
メールのやり取りだけで、何度もすれ違いがあった。
Through emails only, there were many missed connections/misunderstandings and they never met.
Being at cross purposes; a discrepancy or disagreement where people fail to understand or align with each other.
夫婦のすれ違いが原因で、長い間口をきかなかった。
Because of disagreements between the couple, they didn't speak to each other for a long time.
プロジェクトでは認識のすれ違いが大きな問題になった。
A mismatch in understanding became a major issue in the project.