Hi Paride.
I'm actually running Octane 2018.1.3 - 7.08 for Max (2020), and facing this bug since Octane Max V4.xx.
Is I use an IES light and turn it "NOT visible" , and I duplicate this light as instances, the "Main" IES Light remains visible while the instances are not.
The work around is to delete the "main" IES light and create an instance from another instance....
This is clearly a "bug" for me.
Regards.
JC MATIAS