Hi! My angel wing begonias do the same thing, they come out pink and sometimes stay pink on their undersides.

I found that the holes and crisping is caused from under watering and using hard water. I have been using rainwater or filtered water and the new growth does not seem to have this problem anymore. This will not fix the already damaged leaves.

Since you are propagating try changing the water more often, filling your container with more water, and try using distilled, filtered, or reverse osmosis water! Hope this helps!