When I called you - This circumstance is not related in the main narrative. It is likely to have occurred when Jephthah was first chosen leader by the Gileadites, and when Ephraim would probably ignore his pretensions.
Matthew Henry
Concise Bible Commentary
The Ephraimites had the same quarrel with Jephthah as with Gideon. Pride was at the bottom of the quarrel; only by that comes contention. It is ill to fasten names of reproach upon persons or countries, as is common, especially upon those under outward disadvantages. It often occasions quarrels that prove of ill consequence, as it did here. No contentions are so bitter as those between brethren or rivals for honour. What need we have to watch and pray against evil tempers! May the Lord incline all his people to follow after things which make for peace!
SDA Bible Commentary (limited)
Volume 1-7
2. When I called you. The previous account did not mention an appeal to the tribes in western Canaan to help drive back the oppressors. The narrator mentioned only the salient facts.