Copilot selects wrong reasoning effort when changing from a different model

[pedrormonteiro]

Describe the bug

Copilot selects wrong reasoning effort when changing from a different model, the behaviour was identified multiple times and should be investigated

Affected version

1.0.39.

Steps to reproduce the behavior

1. On a new session with model X, change to Opus 4.6 HIGH
2. View message from system saying the model was changed to Opus 4.6 LOW:

● Model changed from claude-sonnet-4.6 (high) to claude-opus-4.6 (low)

3. Change reasoning again
4. Reasoning effort is changed correctly

● Reasoning effort changed for claude-opus-4.6 from low to high

Expected behavior

1. On a new session with model X, change to Opus 4.6 HIGH
2. View message from system saying the model was changed to Opus 4.6 HIGH:

● Model changed from claude-sonnet-4.6 (high) to claude-opus-4.6 (high)

3. No need to change reasoning again

Additional context

macOS
macbook with an M2 pro