@eric Thank you for your response. I will try to answer your questions the best that I can.
I think you understand the problem correctly. To be clear, the ultraRendu is in its Roon Ready mode and shows up in the Roon audio settings as a Roon Ready device. My iMac does not have an SSD only a 1TB HDD. My NAS is a Synology DiskStation 216. As requested, a screen shot of the signal path is below. I should add that volume is set to fixed (100%) and DSP is disabled. My QX-5 does not have a network module so I cannot play Roon directly to it.
I have reinstalled the iPad app, let’s see how it goes from here. If I can’t improve the sound quality, then app behavior is moot. Thanks!