Terminal.Gui (gui.cs) apps via EXE in WSL don't get all keystrokes

# Issue Title

Try running any standalone Terminal.gui app under under WSL via the .exe built by `dotnet build`. Arrow keys and other keys do not work. Some shortcut keys (e.g. CTRL Q don't).

This may apply to Linux in general, but I only have tested via WSL.

# General

- Setup WSL2 with Debian or Ubuntu (I've tried both).
- Install .NET Core 5
- git clone https://github.com/migueldeicaza/gui.cs

```bash
cd gui.cs
dotnet build
./UICatalog/bin/Debug/net5.0/UICatalog.exe
```

Expected:
Up/Down/Left/Right keys work.
Tab/CtrlQ work.

Result:
Only Tab/CtrlQ work.

Note that if you run the app with `dotnet` against the dll it works fine:

```bash
dotnet ./UICatalog/bin/Debug/net5.0/UICatalog.dll
```

I swear this was working before and I don't know if this is a dotnet issue or a WSL issue.

Note that this ONLY happens with net5.0. If `UICatalog.csproj` is changed to use