出会い and 交流: encounters and ongoing exchange
Distinguish an encounter that can begin a relationship from interaction between people.
A new encounter
出会い, read であい, means encounter. 旅先での出会いを大切にしています。 means valuing encounters during travel.
本との出会いが考えを変えました。 says that encountering a book changed someone's thinking. 出会い is not restricted to meeting people.
Exchange between people
交流, read こうりゅう, means exchange or interaction. 地域の人と交流しました。 means interacting with local people.
交流を続けています。 means continuing that interaction. It describes more than the initial meeting.
Beginning and continuation
一度出会いましたが、その後は交流がありません。 says that there was one encounter but no interaction afterward. An encounter and an ongoing relationship are separate.
交流会での出会いがきっかけでした。 says that an encounter at a gathering was the starting point. Context is needed to know what followed.
Does 一度出会いました mean that interaction is continuing?
Show the answer and why
No. It reports a single encounter. The later relationship is separate.