Kevin, it is normal to lose leaves on cuttings. As for the curling, perhaps the cold is coming through the window and causing that.

Hey Kevin!
Leaf drop is nothing to worry about.. The curling of the leaves is not unusual.. Environmental changes will cause that.. You do need to look to see if you have any mites..

Kylie

I am guessing that the leaves curl, and lose their color, turning yellow, then to brown and finally dropping off (or like me, you pick them off because you can not stand to look at them).
I would suspect one, or a combination of either mites, low humidity (dry air), old leaves being naturally shed, or low soil fertility/moisture.
I do not get very excited about it unless I see mites, I feed and water regularly.