Autocompaction not triggered on disk size limit

Hi,

I have a cluster with 5 nodes with each 52GB Ram and 200 GB SSD.
I have set the autocompaction to be triggered on disk size (you can see my configuration in the screenshot below).

I notice that the autocompaction only run when i check on percentage limit but not on the disk size.
It is a limit by node ?
Do i miss something ?