Modify text in grouped shapes

In Visio, I group an arrow with block shape. And the grouped shape will be used repeated in the drawing, except that the text for the arrow and block will be modified in different positons.

However, after the group, all the texts for the arrow and block are locked as well. I cannot modify them until I ungroup the shapes, modify them, and the re-group the shapes, which is very inconvenient.

Is there a good way to solve this?

Thanks