Strange behavior on RollupConditinalSum function on Opportunities

Hi there,

I'm facing a strange behavior on the opportunities and RLI's.

We have the following sugar logic on a currency field on the Opportinities : 


The sugarlogic is triggered only when I update an already created RLI, not when creating.

Is there anything I'm missing ? Can you help me please ?

Thanks a lot and best regards,