Seems like Context.GetODataQuerySettings(); is not loading correctly ODataQuerySettings.

I am referring to code at Microsoft.AspNetCore.OData.Query - public virtual IQueryable ApplyTo(IQueryable query, AllowedQueryOptions ignoreQueryOptions).

I got there from MongoDB.AspNetCore.OData - public override IQueryable ApplyQuery(IQueryable queryable, ODataQueryOptions queryOptions).

I noticed this since [MongoEnableQuery(PageSize = 3)]  seems not to be working (using the sample available at GitHub).