We use Printful, and when something like that happens, it's always because something isn't properly synced between my Etsy store and them. Maybe they stopped carrying that particular blank shirt and I deferred making a decision on a replacement. Or something.
So you should check your Printify account and make sure those items are properly synced with your Etsy store. If everything looks to be in order, wait a bit, they may just be late in picking up the other orders. With Printful, I give them 12 hours. I'm sure you can submit the order manually if they missed it all together.
