Clipper Creek makes high-quality EVSEs that work fine on 208 volts. I have an HCS-50P (50-ampere circuit with maximum of 40 amperes of charging current) at my workshop garage that plugs in to the 14-50 receptacle fed from two phases of the 208Y/120-volt source. HCS-40P (40-ampere circuit with maximum of 32 amperes of charging current) are two options. The HCS-50P allows maximum allowable continuous current from a 50-ampere circuit if the car can use it, but the maximum current the Leaf can draw is 32 amperes on Level 2 under low voltage conditions (my car draws about 30 amperes at 212 volts at my workshop or about 26.4 amperes at 245 volts at home since my utility runs a little above nominal voltage) so the HCS-40P is sufficient for maximum charging rate.
The AeroVironment EVSE I bought back in 2011 that I use at home will also work on 208 volts at my workshop.
Could you post a photo of the nameplate of the Nissan EVSE? The one I saw in the showroom at my dealer did not say 200 volts on it.