There are many causes for high condensing and low suction pressures like oversized compressors, faulty expansion valve, pressure drop somewhere, overcharge, etc.

Also things I suppose you already checked obvious things like not having incondensables and you followed correct charging procedures for R407c and it is in the correct composition.

I would start with the condenser because it is more "off":

Make sure the fan is rotating in the correct direction with no short circuits like open panels. Seal any losses.

Run your hand on the condenser's air intake and make sure you do not feel air at a higher temperature than your ambient temperature (measured far away from any unit). If the temperature at the inlet is higher than ambient or you feel gusts of hot air, you have a hot air recirculation problem.

Check the airflow of the condenser. This is not easy and please don't post back that you cleaned it. Just make sure that the airflow is correct through every little hole in the finns!

For this you either use a anemometer but better still a lantern held from the inside of the unit and somebody watching on the outside the light pattern. If it differs anywhere you may have a blocked condenser and you should use a hard wire to clean it.

If you have any of these problems and solve them you will probably find that the refrigerant charge is low, recharge.

Anyway post back your progress.