VS2017 fails to list Android Unity process in Attach Unity Debugger

I'm having a problem with debugging an Android Unity Application with Visual Studio 2017 on one of my systems. I can debug no problem on the machine MonoDevelop, but Visual Studio doesn't list the AndroidPlayer(...) process when I select Debug->Attach Unity Debugger.

Does anyone have any suggestions as to what might be causing this or how to debug it?

I've tried rebooting the machine / phone and uninstalling / re-installing the VSTU plug-in. Without any benefit.

Thanks

Jules

Repro Steps:
1. Plug-in phone via USB (developer mode enabled)
2. Run "adb tcpip 5555" on command line
3. Unlock phone and accept if required
4. Open Unity 2017.3.0p1
5. Open Standard Assets Example Project
6. File->Build Settings...
7. Tick Development build / script debugging
8. Select Android and hit Build and Run

Example project should build and run on Android phone.

9. Assets -> Open C# Project
10. In VS2017 Debug->Attach Unity Debugger

Observe no AndroidPlayer process in list. Expected result: AndroidPlayer(...) in process list.

11. Switch back to Unity
12. File->Edit Preferences->External Tools
13. Switch to MonoDevelop
14. Assets -> Open C# Project
15. Run->Attach to Process

Observe AndroidPlayer(...) listed.

Software/Hardware details:

Phone Samsung S7
Android 7.0
Windows 10 Pro 1709 16299.192
Unity 2017.3.0p1
Visual Studio Community 2017 15.5.2
Visual Studio Tools for Unity 3.5.0.2