Its going asexual on you. These cycles are common and fairly frequent at times. There is a great probability it will dump its chlorophyll and cloud your tank all up next, most likely at night. This can also be initiated by changes in dKh/Alkalinity. If you don't mind and have the filter feeders for it, great. Otherwise, while it still may contain all or most of the toxins it absorbs for export, export it now and get them out of there and throw that clump in the trash. Thats what and how grape caulerpa should be most used for. Prune it before it spits all that stuff back into the water column.