This system will not operate correctly because the "outdoor temperature" is nearly the same as the "indoor temperature".
The unit is so efficient that too much refrigerant is condensing in the condenser. Remember that this is a critical charged unit, therefore the condenser,evaporator,suction line and liquid line will contain the proper amount of refrigerant. If at anytime there is an unbalanced condition, the system will fail to operate in the prescribed manner. The condenser has too much refrigerant due to the low ambient therefore starving the evaporator thus resulting in lower pressure which results in lower temperature (frost accumulation).
To remedy this situation, block off the condenser allowing the head pressure to build up to a corresponding pressure of a 95*F day. You will then notice the suction pressure will also rise and now is the time to check the superheat.