ArcGIS Pro allows linking 2D and 3D maps to synchronize both maps within a 3D scene in which the 2D draped content is listed in the 2D Layers category and the 3D layers are listed in the 3D Layers category.
When working in an ArcGIS Pro 3D scene, enabling the labels of a layer listed in the 2D Layers category does not display the labels of the layer.
This is a known limitation. Draped labels for 2D layers are not supported in an ArcGIS Pro 3D scene.
Solution or Workaround
To display the labels of the 2D layer, drag the layer from the 2D Layers category to the 3D Layers category. Ensure the labeling of the layer is enabled.
The following figure displays an example of a layer dragged to the 3D Layers category. The labels of the features are displayed on the map.
In some instances, the layer dragged to the 3D Layers category is not drawn properly in the 3D scene. For more information on how a 2D data behaves in a 3D environment, refer to the following document: Get started with 3D.