No sound with Roon convolution filter activated

[Marin_Weigel (Bram Stoker's Cappuccino)]

@Marian

But then, it’s not really Roon’s DSP volume. If I remember correctly, the setting is ‘device volume’, and the device implements it somehow.

The OP‘s screenshot shows DSP volume, and it‘s Roon‘s code executed in the end point (RPi in this case) as detailed by Danny himself here.
To confirm, we would need @Jon_Belak‘s screenshot of Roon’s device setup dialog for his PecanPi.