msplugin missing when Configuring Graph Connector for Confluence Data center

Question

The following msplugin is missing when Configuring Graph Connector for Confluence Data center. When setting up the Data Source in the admin center the data source tries to connect to /rest/api/msplugin/1.0/healthcheck/version. The following error is displayed in the admin center: Invalid Credentials detected. Try signing in with a different account or check the permissions for your account or check if the microsoft confluence plugin is installed.Credentials are correct and also tested with different credentials. Also tested the OAuth authentication but with the same result.

The data source also tries to connect to: /rest/api/content/search?start=0&limit=5&cql=type%20in%20(page)&expand=

This part of the api call is available and works.

I also reached out to support but unfortunately the connector is still in preview. Did anyone had the same issue and is there a way to either install the missing msplugin or work around this