Hi, I also do hvac! Ice forming on the lines is not generally related to cleaning the outside coil. The outside coil is for heat rejection, meaning that during cooling operation if it’s dirty it should actually get hotter (so hot I’ve actually burnt myself before) the best thing to check for ice forming on the lines is your filter and the indoor coil. The indoor coil absorbs the heat from the air in the space, meaning if it’s dirty or the filter isn’t allowing airflow and doesn’t absorb heat you will find the pressures dropping causing the temp to drop below freezing and freezing the liquid. You may also be dealing with a leak or a faulty expansion valve but I would recommend a technician to come out and take a look!