Fighters have an ability that allows them to take 2 actions in one turn (regular, full, unrestricted actions, unlike those gained from the Haste spell):
Starting at 2nd level, you can push yourself beyond your normal limits for a moment. On your turn, you can take one additional action on top of your regular action and a possible bonus action.
Spells with a casting time of one bonus action have the following restriction:
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.
Now, this creates some logical conflict.
As far as I can tell, RAW would allow you to cast 2 any-level spells and one cantrip as a bonus action (if you have one - only Magic Stone and Shillelagh fall into that category).
However, if you were to cast a spell of level 1 or higher as a bonus action, you could not cast any non-cantrip spells with any of your two actions.
This does not make sense at all from a logical point of view (considering "a spell cast with a bonus action is especially swift"). Now while I wouldn't allow casting bonus-action spells with your actions (which is explicitly ruled out - see quote #2), I don't think that the scenario above makes sense.
Are there any passages in the PHB that clarify this issue which I missed? And if there aren't, have there been any developer rulings on this topics?
Addition: If I were to cast a level 1+ spell with a bonus action, could I then use the action granted from Action Surge to cast a non-cantrip spell? RAW, no, but I feel like this ability wasn't taken into account when the rule was created.