Originally Posted by sirdoofus

I haven't grown those varieties or grown plants from bare corms, so I may not be the right person to answer this, however, I would be most concerned about rot. Frequent watering + high temps + lack of roots + lack of leaves to transpire moisture = good conditions for fungal growth and rot. I have learned the hard way here that bananas without leaves are extremely sensitive/prone to rot from too much moisture.

So when I see pics of leafless bananas looking like your ice cream, my first thought is always rot. It certainly may be something else, but the first thing I would do is make sure your medium is appropriate.

If it were me, and I am most definitely no expert, I would gently extract the corm from the medium and have a look at it to make sure there is healthy new root growth. If all looks good down below, then maybe it is something else.

I personally would also consider moving it to a spot that isn't so hot during the day.