The default value for the parameter Initial Radius for radiance estimation = 0.1 % of the scene diameter.
This radius defines the area which connects rays from the camera (camera pass) hitting the scene surfaces at certain points (hit points) with rays from the light sources (photon pass) hitting in their vicinity.
With 0.005 it’s no wonder you got initially bad results. It is advisable to change only one setting at a time and check the render. If you stray too far from the defaults, the render may not converge in a reasonable time.
Glad you got it sorted now :))