There are at least two things you could do to overcome your problem:
- Place arrows and circles in different layers
- Open the arrow properties and add negative values for "Absolute start gap" and "Absolute end gap"
If you know how to create shapes, you could create a circular shape without a main connection point in the center (but a normal connection point). This would allow your arrows to connect to the center in the way you intend. If you don't want to get involved in shape creation I could also provide you with such a shape.