Passive Check executes active check command after acknowledge

Hello,

I have a strange behaviour in my centreon (Centreon Engine 24.10.17).

I´ve configured a passive check, set active checks enabled to no, passive checks enabled to yes, is volatile to no.
 

Also check freshness to no:

Now my Application sends an alert via centreon API and the service goes to warning state as expected.

As soon as I acknowledge the service the active check command (which is a dummy command) gets executed and the service is in unknown state and therfore not acknowledged. Sticky acknoledge works but is unfortunately no option.

So first question: Why is the check command executed on acknowledgement and second: how can I disable that?

Thanks in advance