How can I make a Masked material into a Translucent Object?

I want to get a material, and slowly through a timeline be able to make it go transparent, I’ve already made it so that the Opacity is changed through a timeline, the problem is once I put the new material so I can create the instance dynamic, by switching its outcome to translucent it does a big switch from masked to translucent… meaning it goes from solid to see-through instantly and I’m not sure if its possible to make that a slower shift… everything else as far as making it comepletly transparent works… its just that switching from a concrete object to a transparent one once the translucency is turned on.