Describe the bug
Keytriggers with modifier "ALT" doesn't invoke the command

To Reproduce
Steps to reproduce the behavior:

1. Create a WPF Application
2. Create MainWindow
3. Add a keytrigger with Key="Up" and Modifiers="Alt"
4. Add an InvokeCommandAction and bind Command1
5. Add breakpoints on Command1
6. Run the application
7. Press Alt+Up on the keyboard

Current behavior
Command1 won't be fired
Expected behavior
Command1 will be fired

Screenshots

Desktop (please complete the following information):

• Version with bug: 1.1.122