Hi Imran,
This is based on the Spline direction. Direction means which one is the first point (#0) and which one is the last point (#n).
Typically a good font is created in one direction. Note that fonts are pretty much just Ai paths sorted in a specific document that calls these letters with a particular keystroke. If the specific letter is clockwise, then the next counterclockwise, you might encounter this problem. AFAIK, the first and Segment in a Spline, delivers the initial direction.
Here is a little click that shows how to fix that:
https://www.amazon.com/clouddrive/share/8qhTRcn2cxtycbF6Z5z9XnYONBf3iC9LYtIRvWpJPx4
The Direction can be easily changed.
Let me know if you encounter problems. Please share the path/spline in a scene file here.
Note: You could also try to move from Auto Mode to a specific axis. However, I would first get a direction correctly.
Cheers