I discovered it today and got this answer from Tidal support:
Thank you for contacting TIDAL customer support.
The record labels are in charge of the content in TIDAL, the label is not interested in having
those artists in TIDAL anymore unfortunately.
Best Regards,Erik
TIDAL Support
There are some tracks/albums left but most of it is gone.
Maybe there is some regional differences in what is available.
I’m streaming from Denmark.
We are currently switching our distributor, which is why it can happen that some albums are temporarily not available.
Should be sorted in a few days hopefully.
Now 8 days has past since the artist/albums was removed and added again in Tidal.
None of them are available in Roon I know there is some delay with new Tidal albums in Roon but 8 days is a very very long delay so maybe something else is wrong?
Pleased to hear it. I’ll mark this one Solved so the devs don’t see it as an active issue when browsing. Please feel free to either post again in this thread or open a new one if it should recur.
We should be seeing better synchronisation with Tidal in the future, but it is very helpful to know that clearing the cache can sometimes fix the issue.