سلام و درود
بالاخره با تنظیمات زیر درست شد اما دلیلش رو نفهمیدم
var ST = new string[] { "A", "B", "C", "D" };
var ST1 = new string[] { "A1", "B1", "C1", "D1" };
flowLayoutPanel1.FlowDirection = FlowDirection.TopDown;
flowLayoutPanel1.AutoScroll = true...