Connector Builder

Hi everyone! New to the community. Sorry if I’m posting in the wrong section of the forum.

I’m attempting to build a connector using Connector Builder for Sage Accounting and am running into some trouble. I have the Oauth 2.0 workflow starting, but at the token exchange phase I’m getting an error that says “The auth code you transmitted has an unexpected format.” It appears that the code returned is in the URL-encoded format and hasn’t been decoded before being transmitted.

Example:

GB%2F20cc2677-d838-47e1-a197-e914679d0222

Needs to be:

GB/20cc2677-d838-47e1-a197-e914679d0222

Am I missing an option somewhere or is this a current limitation of the Connector Builder? Any assistance would be appreciated!