why does some of my agapanthus stems curl

I had a flowering stem of my agapanthus grow a little strangely recently. It was curled and off-course, whereas all the other flowering stems were straight and approximately perpendicular. But the wonky stem straightened itself up and grew upright of its own accord a few days later. It sorted itself out.

I had the same problem last year but the stems have split and stayed curled i just thought it may have been attacked by an insect during the winter