I edited your post (removed one image) due to it potentially containing your credentials (I wasn’t sure, but it is better to be safe than sorry).
As to the issue, I am not an expert on our infrastructure myself, but I know for sure that the Cloud Platform orchestrator might be more restrictive as far as configuring your own set of activity feeds.
Was it this plugin from Azure DevOps marketplace?
If so, then I checked the documentation and it publishes the package via the API:
However, the Cloud Platform does not support basic authentication any more and will therefore not work with this plug-in, unfortunately. It will only work for now with the custom installation of Orchestrator that is still based on the old bearer token authentication.