Welcome to the forum! As @Robert_Daines mentioned, the QB9 is not a tested Roon device so it wouldn’t show up in the device list. Can you confirm the QB9 still works as expected on your end, or are you seeing issues with this device? If you are having issues, can you let me know more information as to what the issue is? Thanks!
I have a QB-9 DSD and it works flawlessly in conjunction with Roon on my Mac mini and connected via USB. As stated above, it is not a ‘Roon tested’ device, yet Roon recognizes that it is an Ayre product (just not the specific model). Here’s what the signal path looks like.