Looks like Roon is trying to combine the French electro-pop group with another artist by the same name. Tidal has two separate artists, but Roon is combining them:
@AMP Hi Andrew, this one is horrid, because there are so many bands/artists called “Phoenix”; there’s even a warning on MusicBrainz “Phoenix” artist pages about possible confusion. The source of the issue is either Rovi assigning the wrong one somewhere and/or (more likely) TIDAL assigning the same artist ID to multiple Phoenixes. Will attempt to de-convolve this lot, but it might still be imperfect, particularly when TIDAL is involved.
Closed due to inactivity. If you are still seeing this issue, please open a new support thread.