The 13AJN is a 410 unit. Are you sure they changed the TXV on that coil to a 410 model? Those are a bear to change. A "sharp" contractor would have just put a 13AJA R22 unit on that coil and been fine. Or since you had a deluxe unit, changed the fan motor as others have suggested. You can't flush coils and get all of the mineral oil out. If they tried, there's likely some flush still in it. If they didn't, there's likely mineral oil in your system.
They changed the TXV on The Rheem (air handler) model number is RCHA-24A2GG14. The Ruud 13AJN was the outdoor compressor that was replaced. Could the residual mineral oil account for the coils freezing?