Hi @rachwhit,
Thank you for reaching out for assistance with your door handle replacement project.
What type of paint are you using? How many coats did you apply? Did you use a primer?
The filler itself looks fine; the issue seems to be with the paint coverage and how it is blending in with the existing paint. Unfortunately, it can be tough to blend new paint with old because there will be no transition between materials when they are all applied together, whereas when you are painting over old paint, there will always be a transition. You can, however, blend it in a bit better by preparing the wider area and using the right materials. Patching will often blend in better if you go wider than you'd think, so you'll want to sand, prime and paint an area around 150mm or so in diameter around the handle.
My advice would be to give the area around the handle a sand with some 180 Grit Sandpaper to smooth things out, then apply a primer and two coats of enamel paint in the same colour and sheen level as the existing paint.
Apply the primer and paint in very thin coats using a short-nap roller. Adding some Flood 1L Acrylic Paint Conditioner to your paint can also help to blend in edges.
I think the majority of the issue is down to the paint you've used and how many coats you've applied, but if you follow these steps, you should get a cleaner finish.
Let me know what you think, and if you have further questions, please don't hesitate to ask.
Jacob
