Hmm, it looks like Tidal has silently changed something in their public API 
All requests to https://openapi.tidal.com which I’ve tried return empty responses with 404 error status (I only see a x-cache: Error from cloudfront response header), regardless of whether I am using an API token or not.
Having a look at the official documentation, it seems that they’ve introduced a new “v2 - beta” API, must have been in July 2024, only shortly after the Harmony provider has been implemented…
So far I’ve found no trace of the v1 documentation, no deprecation announcement or an entry in the changelog!?
I will try to find out if I can get the v2 API to work…
P.S. Xythium’s tool still works as that is using a different API (listen.tidal.com, which is intended for internal use).