Used a COG as per instruction 3 3/4"
I have seen many try to balance a biplane by holding it at the given positon on the top wing.
Even if the COG is half a inch of it will hang a bit of horizontally. And this plane will behave badly if it is off by half a inch.
Try to find the corresponding point on the bottom wing and balance it there. When the COG is right and the weight is around 2750 gramms it will fly OK.
It will still be a short coupled biplane with a high wingloading but giving that character there is nothing wrong with it. As with any other plane, there is never magic involved to let it behave good or bad.