the dropping olf the wing at the top of the loop is a sign of a stall,semi symetrical wings produce less lift inverted.then it sound like you got into a flat spin which is difficult to recover from insome designs especially if the flat spin usually has the nose just a tad low not pointing straight down.to recover you need full throtle full down elevater netral airlerons and rudder till the nose drops speed picks up and it goes into a normal spin then recover from that.remember the flat spin from top gun.no control at all till airspeed is regained..definetly send the radio back for repair and what the find.
You have described just what happened! The only thing is that although the nose was not pointing straight down it was more down that flat!.
Oh and let me please ask what does cg is bit too far
aft . mean?
Now, How shoud that manuver be performed correctly? I will be getting another arrow (I dont like flat bottom trainers precisely because I think I can do more with the semy).