It is normal for the Swiss cheese plants to be without holes at their early age. , the leaves begin to split as the plants mature. However, if your plant is mature and doesn’t have split characteristics, then your plant might be suffering from lack of light, under watering, underfeeding, etc. hence, if your plant is young, you only need to be more patient with it. and if your plant is matured, you may need to place it in a bright place and feed it more water. You can also get some fertilizer for it.