ID 379611 - Using the keyboard shortcut "Left + MMB" horizontally rotates the camera instead of tilting when the "Up Axis" option is set to Z

Problem summary
Using the keyboard shortcut "Left + MMB" horizontally rotates the camera instead of tilting when the "Up Axis" option is set to Z. 

Customer reported version
Modo 12.2v1 

Customer reported platform
Windows 10 

Steps to reproduce

1) Open Modo. 

2) Open the Preferences and go to Input -> Units. Under the "Coordinate System" tab change the Up Axis option to "Z". 

3) Use "Alt + MMB" to start tilting the viewport in the Z-axis. 

4) The camera is now rotating horizontally around the origin is instead of tilting the camera in the Z axis. 

Workaround
Unknown. 

Reproduced by support

This bug has been reproduced in:

Modo 12.2v1 - Windows 10 - CentOS 7 - MacOSX 10.13 
Modo 12.1v2 - Windows 10
Modo 12.0v1 - Windows 10 
Modo 11.2v3 - Windows 10 
Modo 11.1v1 - Windows 10 
Modo 11.0v3 - Windows 10 
Modo 10.2v4 - Windows 10 - CentOS 7 - MacOSX 10.13 

Earliest version tested
Modo 10.2v4 - This issue appears to be in all versions of the product.

Expected behaviour
Using the keyboard shortcut "Alt + MMB" should tilt the viewport camera regardless of the "Up Axis" Preference value. 

Actual behaviour
When using "Alt + MMB" with the Up Axis option set to "Z", the camera rotates horizontally instead of tilting.