In some instances, when trying to select annotation features for editing in ArcGIS Pro, the features are not selectable.
The image below shows an annotation feature not selectable even though the Annotation pane is active.
The annotation features are created in ArcMap. Annotation features created in ArcMap are read-only and can only be displayed and queried in ArcGIS Pro. For more information, refer to ArcGIS Pro Help: Upgrade annotation feature classes.
Note: Once the dataset is upgraded, the annotation feature class is no longer usable in ArcMap. Feature classes linked to the annotation are read-only in ArcMap. To ensure the annotation feature class can be used in ArcMap, create a backup using the Feature Class To Geodatabase tool.
The image below shows the annotation feature is now selectable and can be edited, moved, rotated, and so on.