Assembly Hole Series on Mirrored Hole Feature of Part

Hello, I have a part which has identical tapped holes on either end. I drew a sketch on one end and created a hole feature from that. I then mirrored it across the mid plane. However, in the assembly I am unable to select the mirrored side to create a counterbore on the face of a base plate. Is there a solution to this? Thank you in advance.

SolidworksAssemblies