My first try with autolyse was a big mess. I let the dough sit out for an hour, but I didn't cover it up. I was so caught up in the fancy term that I forgot the basic step. The gluten did develop, but the dough was too dry to knead properly. What's your go-to time for autolyse?
My first autolyse I forgot to cover it too, ended up with a dough skin like leather. I usually stick to 30 minutes for most recipes, that seems to be the sweet spot. Any longer and I start running into the same drying out problem you had.