What does Judges 12:4 mean?

Then Jephthah gathered all the men of Gilead and fought against Ephraim. The men of Gilead defeated Ephraim, because the Ephraimites had insulted them, calling them fugitives from Ephraim living in Gilead. Judges 12:4 - Modern Text Bible

(A civil conflict breaks out, and Gilead defeats Ephraim, partly because of Ephraim’s insults and arrogance.)