I investigated this, and discovered that AssemblyTitle on its own is not sufficient. The title will then not appear in Task Manager, as you found out. You need to supply with more attributes in order to make this attribute work, but I don't know which ones makes the difference.
This is a file from a project of mine originally created in VS2015. If you use it in VS2013, remember to generate a new GUID for each assembly where you use it. You can do that somewhere in the main menu of VS. Or you can buy
quality GUIDs made in China.
AssemblyInfo.fs
namespace SecondDemo.AssemblyInfo
open System.Reflection
open System.Runtime.CompilerServices
open System.Runtime.InteropServices
// General Information about an assembly is controlled through the following
// set of attributes. Change these attribute values to modify the information
// associated with an assembly.
[<assembly: AssemblyTitle("SecondDemo")>]
[<assembly: AssemblyDescription("")>]
[<assembly: AssemblyConfiguration("")>]
[<assembly: AssemblyCompany("")>]
[<assembly: AssemblyProduct("SecondDemo")>]
[<assembly: AssemblyCopyright("Copyright © 2017")>]
[<assembly: AssemblyTrademark("")>]
[<assembly: AssemblyCulture("")>]
// Setting ComVisible to false makes the types in this assembly not visible
// to COM components. If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[<assembly: ComVisible(false)>]
// The following GUID is for the ID of the typelib if this project is exposed to COM
[<assembly: Guid("827700cd-54f6-4485-9239-fbd6af43c3e5")>]
// Version information for an assembly consists of the following four values:
//
// Major Version
// Minor Version
// Build Number
// Revision
//
// You can specify all the values or you can default the Build and Revision Numbers
// by using the '*' as shown below:
// [<assembly: AssemblyVersion("1.0.*")>]
[<assembly: AssemblyVersion("1.0.0.0")>]
[<assembly: AssemblyFileVersion("1.0.0.0")>]
do ()