Bought book from in-game store, but it has no effect.

Hi guys, I just bought book "Raising Spirits" in the in-game store for 99 fuel. But it turned up that book doesn't have any effect: it has no effect % indicated, nor the morale stat show any effect from the book. Please give me back the fuel I've spent on it.

other users complain about the same: https://discord.com/channels/1145726192939454568/1442193018789691392/1541221758965915718

Same here. I've bought one and it have no effect at all.