When riding at a constant speed, is the board supposed to be nearly flat, tip slight down, or tail almighty down?
I feel most comfortable riding with top slightly down or flat but the board intermittently wants to slightly tip up - I don't think it is pushback as battery is full and I'm going cruising at 12-13mph
Make sure your board isn't in Elevated mode, it should be in extreme mode.
Also, check your tire pressure. At lower pressure the boards tends to "feel" like the nose is slightly lower (for me anyway).