The center of gravity noted in the manual is too far aft. The CG should be 2.75–3.5" (70–90mm) behind the leading edge of the wing.
1 Authorized Warranty Period (Date of Purchase)
What this Warranty Covers
Horizon Hobby, Inc., (Horizon) warrants to the original purchaser that the product purchased (the "Product") will be free from defects in materials and workmanship at the date of purchase.