The best way to diagnose X-Plane problems – particularly calibration issues is to look at the datarefs.
There are two ways to do this – Using the built-in dataref display or using a freeware plugin called DataRefTool

For example, we often need to check the actions of the parking brake:

You can set a dataref display to show in the screen by clicking Settings –> Data Output and selecting Gear and Brakes:

The display will look like this:

Alternatively, use the Dataref plugin which shows more information and is much easier to read:

To get the Dataref tool go to the DataRefTool web site and download it. The documentation is on the site. This tool is particularly useful for seeing how often the dataref changes by colour-coding the display.

The Dataref tool was created by Lee C Baker is works with X-Plane 11 and X-Plane 12

Once you have finished tinkering, make sure to completely disable the dataref tool plugin before actually flying.