How to reproduce:
1. Open the attached project
2. Connect your device to your WiFi network. Make sure that you machine runs on the same network
3. To enable Visual Studio Community source level debugging check that the Editor Attaching option is enabled in the Preferences on the External Tools panel
4. Synchronise the Unity project with the Visual Studio project (menu: Assets > Open C# Project)
5. Make sure that Mono Scripting Backend is selected in Player Settings (menu: Edit > project Settings > Player > Other settings)
6. Make sure that the Development Build and Script Debugging options are enabled in the Build Settings for your target platform
7. Build and run test scene on a device
8. When the app is running on the device, you can select Run -> Attach To Process in Visual Studio, this will show the full list of debuggable Unity processes.

Result: Android or iOS is not listed as one of the targets

Note: if one is trying to debug on iOS, he/she should Stop XCode, manually find and launch application on device and then repeat step 8.

Note:
- I also tried using ethernet cable on mac.
- Tried connecting Android device this way https://docs.unity3d.com/Manual/AttachingMonoDevelopDebuggerToAnAndroidDevice.html
- Tested and MonoDevelop, it connects for debugging.

Reproducible: 2018.2.0a1, 2018.1.0b2, 2017.3.0f1

Tested and reproduced:
Samsung Galaxy S8,
iPhone 6Plus, iOS 11.0.1

WON'T FIX: This is a bug in VSfM.