When you finally distill your product, you will see first a small fraction of safrol, then another fraction of iso and then the ketone, with a yiled of may be 60 % molar from safrol. With single distillation you'll have a bit of saf and iso with your ketone, it will react the same. Store it in the freezer immediatly.
I've not performed this rxn, but I understand it. It seems that when you distill some solids could appear in the refrigerant and even contaminate the ketone, it is because benzoquinone sublimes. Make the washes correctly and good luck..