On the hero selection screen for any game mode, the game only allows me to click ready with free to play heroes. None of the heroes I own are showing and in fact I can purchase them all again from the shop.
Same for me… can only take the free heroes
Not only heroes, but banners, sprays, mounts are missing too…
Same problem 
even sometimes I cannot pick any heroes
same for me, I can’t pick most of my heroes
Make sure you are logged into the correct region.
Given that it is taking me 30 minutes to even login to battlenet, there might be some underlying server issues at the moment.
Checked that first. That’s not the issue sadly.