If this is a common problem for you, you can try to bread the cutlets and then refrigerate them for at least 30 minutes before frying. It's also worth to pat dry the cutlets with paper towels before breading them. Make sure to shake excess flour and egg while breading the cutlets. Make sure the oil is hot enough and keep them cooking briskly, if you lower the heat too much they will soften and coating will fall off. If you don’t think they are fully cooked inside when brown then put them in the oven for a while before serving.