Run /model after your task to see. Mine keeps downgrading to Opus 4.8, which is a problem because Opus 4.8 keeps no-oping critical security code.
There is in /config "Switch models when a message is flagged" now which can be set to false, but I had no chance to see what happens then, does it just stop or what.
What you're describing only applies to security or biotech downgrades. A downgrade related to the model believing that you're doing something related to model development is invisible and silent and internal.