Business Central and KIE Execution Server - integration defect

We are currently running JBPM 7.41.0.Final (Business Central) and a Spring Boot implementation of KIE Execution Server (using 7.41.0.Final dependencies).

On attempting to upgrade to newer versions (7.51,55 and 59) we have encountered issues with connecting the KIE server with Business Central (BC).

Specifically when the initial request to register the server is made to the BC controller endpoint, the DEBUG logs clearly show "NOT_ATTEMPTED" for each authentication method.  We have only imported in our setting to standalone.xml which are required for registering MSSQL driver, connecting to MSSQL DB and integrating with LDAP.  Furthermore, we have always just had one system property "org.kie.server.token" set with JWT token value (needed to authenticate to our KIE server).  We have never had issues with KIE registering with BC in previous versions.  We have even tried setting "org.kie.server.controller.token" with our JWT token value in order to provide a valid authentication header for BC to use.  We are on a time critical project and we are not in a position to add in additional authentication components to the architecture (such as KeyCloak).

Due to the sensitive nature of this project, it is not possible to share full configuration files or architecture, but after following the documentation for each version we have tried, we have had no success. Often the BC server.log shows that authentication from the KIE server has been attempted using the default kieserver user/password, despite alternate means being defined (as per documentation) within the standalone.xml file as described above.

The latest BC and KIE combination we have working is BC 7.41.0.Final with KIE server 7.51.0.Final.  

We would greatly appreciate if this could be investigated.