Glad if it helped 
What does it say when you click the spinning icon? There should be a message displayed. Maybe it’s simply not finished with the importing.
(Normally, when all is finished, there should be no spinning icon, Full Disk Access or not. (Even if it has Full Disk Access, it only imports music from the locations that you set up in Roon > Storage)).
You can, by the way, choose whether the audio analysis during importing uses most or all resources (in which case it’s faster but using Roon in the meantime may be choppy) or if it shall be benign and analyze more slowly, but leaving resources for interactive usage. You do this in Settings > Library > Background Audio Analysis Speed.
In any case, depending on the size of your library the importing may take some time. I’d give it time, the spinning icon does not hurt anything except being annoying.
It’s also possible that the metadata retrieval got stuck during importing, and then the icon is also stuck spinning. In this case, you get the “Metadata improver: Halted” message when clicking the spinning icon. In this case, a reboot of the Roon server should normally make it go away.
Finally, it is possible that it got stuck on a corrupted file or problematic file tags:
There is currently a known issue where some albums can displayed twice, even though they actually exist only once. Maybe this affects you.
The sign for this is if you select one of these albums (by performing a rightclick on the album, or, on the Mac, you can also Ctrl-Click. On phones and tablets, do a long tap on the album), then both show as selected. In addition, the number of albums shown under the “My Albums” heading is wrong, i.e., it shows “xxx of yyy” while xxx is a higher number than yyy, which should be impossible.
The issue goes away temporarily if you restart the Roon server, but may come back with time. (A typical trigger seems to be if you sort My Albums by artist names and then scroll for a while).
This was reported by me and others here:
(Note: this is a long-running thread that lumps various similar issues together. One issue was a splitting of Various Artists albums into two or more parts, with each having only a subset of the tracks. This were resolved, but the visual duplication is different, insofar each duplicate shows all tracks and they have the described behavior when selecting one of them. This issue seems to have recently come back or was not ever completely solved, it’s unclear)
and here:
Roon is working on this, hopefully they will really fix it this time around. Until then, I recommend:
- Reboot the Roon server, to limit the occurrence of the issue.
- If you are not sure if an album really exists twice or is only displayed twice (or more times), perform the selection test as described above.