This is probably water related. The crimson sweets might have blossom end rot which we usually see on tomatoes and peppers. I have seen it a couple of times on watermelon. Usually blossom end rot can be controlled through proper watering. If the melon does not get enough water, it does not get enough calcium to develop strong cell walls and the blossom end of the melon sinks in.
Your allsweets may also be needing a more steady supply of water. The deformed shape could indicate that part of the melon is getting enough water and trying to develop normally and part of it is not.
Water regularly so the melons do not undergo dry spells. Mulching can also help to conserve moisture.
