"Times Slept in a Bed" statistic increases by just laying in bed and even when not skipping the night

The bug

I am trying to make a datapack, so I used minecraft.custom:minecraft.sleep_in_bed. When I sleep in bed, the point will add 1 before I pass the night. So each time I sleep in the bed and get up manually, I will add 1 point.

How to reproduce

1. Run the following commands:

   /scoreboard objectives add Slept minecraft.custom:minecraft.sleep_in_bed
   /scoreboard objectives setdisplay sidebar Slept

2. Enter a bed, and then leave it
   → The score increases, even though the night was not skipped