When you open up the Starship item list you can filter by type at the bottom, there is Starship frames in there and you should find everything. You should be able to search for the name of the frame (let's say explorer) in the search bar and it should show up. These work for me when I put them into a new starship sheet.
I can reproduce this, I tried some other combinations of races themes and classes (where classes should be the only one that matters for this). It seems to be a general issue. Once you level up to level two it correctly calculates the Stamina Points.