There are several tabs in Katana that use the Tab key for certain actions. Some, but not all, are:
Node Graph tab, to display the node list.
Monitor tab, to swap to the Catalog view.
Viewer tab, to cycle through manipulators, or display the Measurement Tool manipulator.
Typically, when the Tab key is pressed, the key event is processed by the tab under the mouse pointer. However, if a widget has the focus (e.g. an input field or a combo box), then the key event is not sent to the tab under the mouse pointer. Users may describe this as unreliable functionality of the Tab key, as sometimes it is not obvious that a widget has been focused. In that situation, all the Tab key events would appear to be consumed unreliably.
Steps to reproduce:
Launch Katana with a Node Graph tab and a Parameters tab.
Add a TeapotCreate node.
Set the edit flag on the TeapotCreate node.
In the Parameters tab, set the focus on one of the parameters (e.g. the name parameter).
Move your mouse pointer over the Node Graph tab.
Press the Tab key.
Actual behavior:
The focus widget in the Parameters tab will change to the next widget.
Expected behavior:
The node list menu in the Node Graph tab will be displayed as usual.
NOTE: The Tab key could also be assigned to custom keyboard shortcuts, which would present the same issue described here.