This is in line with a change made to sun enchantment treasure cards a while back, where enchanted cards would no longer be considered treasure cards after being enchanted.
I can't see how this would be intended to happen, so I'm reporting it here. I'm too lazy to look further into it without confirming it's actually a bug first though. I haven't tried other sun spells or other AOE spells. If it were up to me, all spells would follow the same logic.
