Sign-In System: Rewards Are Stolen from Others

One kun year has passed. Chen Huang has traveled through one kun year. He has begun to doubt. What is he doubting? I doubt the system. Like many time travellers, Chen Huang awakened to the system and the local sign-in system. Logically speaking, signing in at the first place should be very simple. Yes, it was Chen Huang's birth point. The problem is, don't just focus on signing in. You must sign in successfully. What does it mean to keep failing? And how come the rewards you give are all other people's things?