Charlie sure doesn't look like my Dwarf Cavendish. However, the Dwarf Cavendish group has quite a variety of cultivars.
He does look like a picture of the Super Dwarf Cavendish on
www.webebananas.com
The SD Cavendish gets to be about 3 feet tall. Having Charlie in a pot will reduce his size as compared with having him in a garden in Florida.
How old is Charlie? If he is tissue cultured, he could take several years to reach full height.
Perhaps Charlie has a size complex and you haven't been cuddling him and reassuring him enough.
Allen