Inventor does not allow users to enter pin names in the same uppercase and lowercase letters. For example, you cannot create "A" and "a", "B" and "b", "C" and "c", and so on, in one connector. Inventor treats the pin name "A" and "a" as the same name while the connector manufacturer designates two different pins in this way.
Attempting to use such pin names returns a window with a warning message with no option to ignore the message and proceed further.

For the electromechanical design to work correctly, Inventor must have the same pin names as in the electrical diagram in AutoCAD Electrical. In turn, the electrical diagram must have the same designations as in the electrical component data sheet.
Below is a photo of an example Eaton connector from their product catalog. This connector uses pin names that cannot be assigned in Inventor.

So it would be a good idea to add support for the same uppercase and lowercase letters in pin names for one connector to Autodesk Inventor.