Soft spots on stern of bravo

Purchased a used bravo a few months ago. Still haven’t sailed her. Anyways I assumed since it was made of Polyethylene I didn’t need to check for soft spots. I was prepping for my first sail and noticed one side of the stern is soft and not firm like the other. I looked in through one of the drain holes and noticed the shell is lined with foam. The foam is cracked on the soft side. Is there a fix for this ?