Ball and Coupling

New to 3D Printing, just getting started.

I am trying to print a dummy 13. I am using a Flashforge Adventurer 5M Pro, 0.4mm nozzle, Orca Slicer.
All prints come out well, except the ball and coupling’s.

I understand the ball is going to be flat on one side. But it is like the ball is not round \ big enough, due to it slipping in and out of the coupling socket part.

I have tried setting the speed from 50mm/s to 12mm/s, setting the layer height from 0.2mm to 0.1mm,
went from a 0.4mm nozzle to a 0.25mm nozzle nothing worked, same result.

Thank you in advance for any help.