Missing logs cluster green to yellow

Hi,

in the Observability > Logs section I am filtering all the logs containing "Cluster health status changed" string (I also tried "YELLOW" or just "Cluster health status").

I get these results:

I was wondering why I don't see logs of the cluster transitioning from GREEN to YELLOW state, but only the transition back YELLOW to GREEN?

It is just out of curiosity.
Am I searching the wrong thing, is it an expected behaviour or else?

Thanks,
Nicoletta