Hi,
This has been going on for a while and I made a post on the EU forums as well. When there’s more than 5 (Traditional HS) hero skins in the shop, the last row is not displayed, this happens on mobile and desktop for me.
For example, this week, the “Iron Hunter Rexxar” and “Hatcher Gul’dan” skins were added to the shop but I can’t see them on my Europe account. When I switch to a different region where I have none of the skins that are being sold, I can see them all. It happened a few times that the skins that I was not able to see were missing in my collection and I was not able to buy them because of this bug. (RidiculousHat helped me and some others on one occasion, the solution required us to restart the client)