Hi, you have extended the Deadline to Saturday, May 5, 2018 UTC
but on designers' side Project status looks - Closed (Pending Selection)
thus new designers can't submit their ideas

Maybe you see status "Open - Deciding" from your customer account
yet if you put contest link in browser not being logged in the account -- then you see - "Closed (Pending Selection)"

could you upload some examples of rock concert admission ticket/posters that you like?