Do your interior shutters have a free-wheeling louver that no longer subscribes to the uniform position of the others? This louver has somehow escaped the control of the tilt bar dictator and now revolves in whatever direction it pleases.
Somehow one of the shutter staples that connects the tilt bar to the louvers has become dislodged.
This is a simple repair with just a few moments of your spare time. If you still have the staple, dip the ends in a little wood glue, hold the center with a pair of needle-nose pliers, slip one in through the staple in the tilt bar, and push into the corresponding holes in the louver. If the holes are gone, rotate the louver a half spin, and you will find them on the opposite side.
To create a new staple, fashion a new staple from a large staple gun staple. Bend the staple into the same approximate shape as those currently in place. You may need to snip off the ends if the staple is too long. Then follow the instructions above.