Porcelain Vine...WAS variegated

Last Spring I planted two vines of Variegated Porcelain Berry 'Elegans'(Ampelopsis brevipedunculata). This year, all of the new leaves are completely GREEN on both vines, growing from the same 12'ft woody growth which had highly variegated leaves marbled with white last year (from spring to fall). Has anyone else ever have this happen? The only thing which has changed from last year is that it continues to be an unusually cooler and rainy spring in zone 5.

I just found this little bit of information. Maybe if you cut it back, the variegation will come back from the new growth. Just guessing here. Mine was cut back this spring and looks okay at this point. At first I didn't think it was going to be variegated again, but it is okay.

Porcelain Berry—Ampelopsis brevipedunculata
Hardiness: Zones 4-8
Great for rapid cover of unsightly objects, this vine will grow 15-20 feet in one season! It can be cut to ground in spring to maintain. Its berry fruit develops with a yellow hue and slowly transitions into pale lilac and finally into amethyst blue; it's very effective in September and October.