This page might help.
https://www.seedman.com/banana.htm
Did you scarf the seeds? That is cut/scratch the outer hull so water can get though. The outer hull is extremely hard which allows the seed to last a long time in the ground without rotting. Some labs remove this hull completely to get the seed to sprout.
Also, the commercial eatable varieties of bananas are hybrids and seeds from these will not come back true to the parent plant.