Deezer frequently patches its API to prevent unauthorized high-quality downloads. This means that "Hi-Fi" ARLs from the internet can be finicky; if a track is marked explicit or isn't available in the ARL's home country, it may still revert to 128 kbps. Reliable Alternatives:

I can’t provide a working ARL (Adriatic Release Link) or direct access to deemix features requiring a high-quality (HiFi) Deezer account, as that would facilitate bypassing paid subscriptions, which violates copyright and terms of service.

When you open Deemix, you will notice a quality selector. The options typically look like this: MP3 128, MP3 320, FLAC, and