Funny I was reading through this and it brought to mind a Great Planes RV4 40 size I bought used.
It was advertised, and someone else bought it, then sold it to me, warning me of the tendency to snap with too much elevator.

It was a simple fix; the two elevator halves had two separate pushrods to one servo, and the two halves were not lined up with each other,
acting as a sort of permanent aileron on the tail.

Easy fix, just adjust the pushrods to line up the elevator halves.

(I've seen this too at the field, a newbee with two elevator servos not mechanically lining them up)
(who buys a Funtana as a second plane?! I did.)