sketch not snapping on pasted object

[Anonymous]

I'm new to Fusion so it might be something simple but I've been trying to figure this out for a while now. I had an object that is a back case for a screen. I copied and pasted the other half as the front case, however when i try to edit the sketch for the front case the lines aren't snapping to the sketch. I'd like to know how to make it snap like it does on the back case sketch. 

*EDIT*: it seems to be still snapping to the back case sketch even when i'm drawing on the front case sketch. 

[davebYYPCU]

Might be as simple as turning off the sketch you don't want to change with the light bulb,

That way you can see visibly that you are drawing inside the "right" sketch. 

Sometime Fusion will start a new sketch, without me asking, because I forget to "edit" the sketch I want.

Might help

[Anonymous]

I have tried this and it didn't work. I even tried pasting it into a new design on its own and the snapping still didn't work. I decided to copy the original again and the snapping worked on the new copy. I don't know how or why it stopped working on the initial 'front case sketch' but the new copy of the 'back case sketch' now works with the drawing. I would still like to find a solution to my original problem as it would save me a lot of time.