Hello,
What you’ll need to do if you want to adjust the acceptance radius is use Move To Location, even though it does require an AI Controller.
It may help to understand your issue if you can provide a bit more detail, and some screenshots, on your setup.
But in terms of the Simple Move To node, take a look at the post linked below, as it contains some useful information that may help you find an alternative to Simple Move.
Have a great day