Thank you so much! <3
Ah, I see, you are not doing anything wrong, it's just really likely that the light bouncing is disabled on the low and medium lighting quality
Go to the settings > Graphics > Lighting Quality and set it to High (or Very High). This should enable Lumen (light bouncing) and it will light up the game greatly, without tanking too much performence!
This has already been looked at, and it will be investigated and fixed in the upcoming update.
Thank you for the notification (and positive review) and I hope this helped you with your problem! ^˘^