Hey Ben, this is from and old thread but may be what you need…
The thread is “Can’t get to engrave mode…”
I had the same issue. I had to go through the motions as if I’m subscribing and tapped ok. Only then did it see the subscription and the subscribe buttons disappeared. It took a bunch of tries to get it to work. The Restore Purchase did absolutely nothing. I had this happen on two iPads.
Note the “it took a bunch of tries…”
-- Jim