Hi @Allen_Wong and welcome to the community.
First of all you are not using an outdated docker image.
I think your configuration might be the problem. You mentioned, you are using jwt_scope_to_policy_mapping, so I assume you are using JWT authentication. Could you review our documentation on JWT scope to policy mapping support.
You also say that when you merge them into a single policy it works. Are there changes to your API definition and policy definition when you do? Maybe sharing your API definition might help.
Edit
Linked the wrong doc initially. Modified it now to point to the correct endpoint