It's from the interaction with the planet effect. The code runs when the card is discarded from the hand at the end of the turn, so with it not getting discarded it isn't counting as reserved. I will have to update that.
As for a debug mode, I do already have a hidden dev control system in. If you hit Alt + ` it toggles its visibility on or off. There are some buttons for free production and one for resources I believe.
Edit 5/4:
Looks like I actually did account for cards remaining in hard to trigger the effects. I just forgot to hook up part of the code so while the stored value increased it was never displayed and never actually applied when the planet was played.