[Discussion] Massive quality drop in "Cover" function since Jan 29? (Style shift & Wrong chords)

Hi everyone,

I suspect there was a silent update or a model regression around Jan 28/29, 2026, specifically affecting the Cover function.

I have a stable workflow that was working perfectly up until Jan 28. However, starting yesterday (Jan 29) and continuing today (Jan 30), the results have degraded significantly.

Here is my testing context:

• Reference Audio: Same track used previously.
• Prompts: Identical Style and Lyrics prompts.
• Persona: Same Persona ID.
• Settings: Exact same parameters.

The Issues Observed (Jan 29 - Jan 30):

1. Drastic Style Shift: Despite using the exact same inputs, the output style is completely different from what I generated just two days ago. It feels like the model is ignoring the nuance of the prompts.
2. Musical Errors: There is a much higher probability of wrong chords and dissonance. The musicality has become "unpleasant" to listen to.
3. Consistency: I tested this across several of my other mature prompt templates (which usually produce consistent high-quality results), and they all suffer from the same degradation.

Has anyone else experienced this sudden shift in the last 48 hours? It feels like the logic for how the Cover function interprets style has been fundamentally changed or broken.

Any insights would be appreciated.