Subclass has much fewer spell slots than other subclasses / non-subclasses

I just noticed this - if you set a character’s class to ‘Tempered Psion’ and subclass to ‘exomancer’, the character suddenly has 0 cantrip slots and far fewer spell slots (11 at level 20) than other subclasses. This seems very strange and to my knowledge subclasses cannot / should not normally affect spell slots.