Troubleshooting email signatures in Exchange can be difficult. To make sure your signature is configured correctly, here are some steps you can take:

1. Check that your signature is correctly configured in Exchange.
2. Check for any Outlook client configuration issues.
3. Make sure that the sender’s permissions and rules are not conflicting with the signature.
4. Inspect the code in the email signature for any HTML errors.
5. Try creating a different signature configuration and testing it in Exchange.