There aren't any bugs reported for the daily bonuses, so the only reasonable explanation is you didn't log in on Monday. You logged on Tuesday and didn't notice you did not receive daily bonus. Logging on Wednesday is 2nd day in a row logging to the game so you get daily reward for Day 1, tomorrow you will get day 2 (if you log) etc. till next Monday when you will get the 100 gems (if you log daily ofc.) and counter will reset - next Tuesday will be Day 1 again.