You should limit the action of the explorer during the first missions

'm stuck in 1 of the tutorial mission:

I need to send my new army to a nearby sector to fight a bandit camp. Right now the sectors are not revealed (fog of war) If I understood well only explorer can reveal sector. My issue is that I already sent him to a "treasure hunt" so I need to wait like 4 hours now until he comes back. I thing that this "treasure hunting" option should be deactivate during the learning missions and unlocked later in the game.

Best regards,