[come] into conflict

to experience a clash or disagreement, often due to differing opinions, interests, or goals

The two political parties came into conflict over the proposed tax reform.
Sibling rivalry can occur when children come into conflict over parental attention.
At the border, tensions flared as the two neighboring countries came into conflict over disputed territory.
Cultural differences can cause individuals to come into conflict with each other if not properly understood and respected.
The two rival companies often come into conflict over market share and customer base.