Does it matter on which phase the solar panel inverter is connected?
Being a grid-tied installation, it's quite possible that the power utility had some say in which phase to connect the PV system to.  In 3 phase systems, it's necessary to balance the load as equally as possible between the 3 phases but this is difficult to impossible to do within a single household.  So the utility designs the distribution network so that a group of homes share the load across the phases and over a large number, the phases are well balanced.

When connecting PV equipment to their system, generally the utility will provide specific instructions on interconnect based on the capacity and type of your system.  You may not have been aware of this as the installer was likely the one receiving the instruction, not you.

You might check with the installer as to the reasons why they hooked it up as they did.