I'm sure a proper fried chicken expert will help out but in the meantime...
Here's what I do.
Re egg wash: I make mine very 'strong' for crumbing: nearly all egg, just a dash of
milk.
Are you dredging the chicken in flour before the egg wash?
That makes a massive difference- flour sticks to meat, wash sticks to flour, crumb sticks to everything
Another thing I find helpful is to us a dry, rather than moist crumb.
If using actual breadcrumbs, I'd dry them right out before breading the chicken.
The dry crumb sucks up moisture from the wash, and kind of glues itself there.
put a thick layer of dry crumb in a wide container, keeping the rest in a bowl.
Gently lay a few pieces at a time in the mix and rain crumb over them till totally covered.
Gently push the crumb on, turn the chicken and cover any bald spots.
Careful handling is important during every step as it's important to keep the flour/wash/crumb layers as intact as much as possible.
In my
experience, frying crumbed things as quickly as possible after breading makes a big difference.
If you have to put it in the fridge, coat the container in plenty of crumbs first.
Shake off loose crumbs before frying.