Hey @GeoffD – unfortunately, the handling of multi-disc sets in Sooloos leaves a little bit to be desired. While Sooloos understands disc numbers (ie, Disc 2 of 4), it doesn’t have any concept of a multi-disc set, so it’s possible Roon isn’t understanding these exported files as all being part of the same set.
My recommendation would be to make sure it’s clear to Roon that the discs are all part of a single album. The best way to do this is to make sure the tags indicate this is a set, as described here, and to make sure the files are organized on disc in a way that indicates they’re a set, as described here.
I would make some changes as described above, and see if the albums group on their own. If they don’t, either select the discs in Roon and choose Edit > Re Scan, or just rescan your entire folder by navigating to Settings > Storage and choosing Force Rescan next to the drive in question.
Let me know if that helps Geoff or if you’re still having issues. Thanks!