Happiness resets every 15 minutes of the hour. If it is OVER your maximum, it will reset back to that on every 15 minutes of the hour. MikePence has posted the Wiki page explaining this above.
Just to confirm for you though, here is the logs around the time of the report.
| 05-01-2020 02:42:49 | Kittycat_clover ate a Big Box of Chocolate Bars gaining 35 happiness |
| 05-01-2020 02:29:58 | Kittycat_clover ate a Box of Chocolate Bars gaining 25 happiness |
| 05-01-2020 02:29:57 | Kittycat_clover ate a Box of Chocolate Bars gaining 25 happiness |
| 05-01-2020 02:29:56 | Kittycat_clover ate a Box of Chocolate Bars gaining 25 happiness |
As you can see, you used candies too close to the reset (02:30 in this case), and would have lost any extra that you had.
Sorry!