Those frequent elevator movements remind me of an aircraft I was flying on the weekend. It was an absolute death trap. No wonder the 200 hour owner is ****e shared of it.
I won't say what it was other than that it is of the wild FELINE variety.
I will be talking with the manufacturer and asking for his idea on how to resolve the issues. Although it just occurred to me that the manufacturer crashed his own model at a Qld fly-in recently. I must look that up.