Hey everyone!

I have a white clematis. Sorry, I don't know the variety, tag is long gone. The flowers are smaller than most varieties. It has bloomed white for 3 to 4 years, no problem. This year the blooms are 1/2 green and 1/2 white and the flower petals are kind of curly, the buds look weird but the leaves don't look bad. I've tried to find info online and don't see anything like this. Has anyone had this happen and if so, what do I do? Thanks in advance!