Hi All and @AdamMartin
I was wondering if anyone has encountered the following issue:

in ArcGIS Pro (2.9.3) while creating a New Investigation Graph for ArcGIS Knowledge Server 10.9.1.
All certificates and licenses validate successfully but when I want to create a New Investigation Graph I get this error despite the blank graph item is created in Portal content after running the tool in my client's environment and the logs don’t show anything helpful.
I've also tested creating the new investigation in ArcGIS Pro 3.0.2 in my laptop to my client's portal environment, it creates a different error:

Any advice/help is appreciated.
Thank you.