It seems like you are experiencing an issue with the IK stretch not working as expected. Based on the information available, there are a few things you might want to check:

1. IK Constraint Order: Ensure that the order of your IK constraints is correct. Sometimes, the order can affect how constraints are applied. You can refer to the Constraints: Order documentation for more details.

2. IK Stretch and Softness: Note that the Stretch and Softness options in IK constraints cannot be used together. If you have both enabled, it might cause issues with the stretch functionality.

3. Bone Scaling: Check if any parent bone is scaled, as this can affect the IK behavior. It's recommended to use the bone length tool instead of scaling bones to resize them.

4. Project File: If possible, try to replicate the issue in a new project or check if the problem persists in a different setup. Sometimes, starting fresh can help identify the root cause.

If these suggestions do not resolve the issue, you might want to review your setup or consider sharing your project file for a more detailed investigation.