I was working on using query.health to make the score on the scoreboard the same as the player's health.
In the process, I found out that while the health was recovering, query.health was returning a value that was missing 1 from real health.
I talked to other people just in case it was an add-on problem that I designed, and I met someone who knows about errors related to absorption.
In the process, I got the "health_query_bug" add-on that I put up as a file, and after testing, I was convinced that the query was the problem.

The exact questions I found during the test are as follows.
1. After suffering damage, the first recovery recovers two degrees of health.
2. At this time, the query recognizes that 1 health is recovered.
3. In the end, After the health is max, query recognized as max health after a time of recovery.

If number two is not a problem, but number one is a problem... I think it could be a matter of Minecraft itself.