Graph created OneNote not recognized as "Site-Notebook"

bratukha 

The Problem is that the Website-Feature "Site Notebook" is not activated.

As a Workaround, you could enable the WebSite-Feature Website with CSOM something like this:

SharePointOnlineCredentials onlineCredentials = new SharePointOnlineCredentials(serviceAccountUsername, serviceAccountPassword);
ClientContext ctx = new ClientContext(rootSiteWebUrl);
ctx.Credentials = onlineCredentials;
ctx.Load(ctx.Web, w => w.Features);
//Activates Feature SiteNotebook
ctx.Web.Features.Add(new Guid("f151bb39-7c3b-414f-bb36-6bf18872052f"), true, FeatureDefinitionScope.None);
await ctx.ExecuteQueryAsync();