Summary:
Default value for Textinput is ignored in Group field type
Detailed Description:
If i set a default value for a textinput field in a Group field type, the
default value is ignored beyond the initial row.
So all subsequent rows the default value is missing for the textinput field.
Same goes for textarea fields (editor) in a Group field type, where only the
initial row sets the default value.
I also have a dropdown field with a default value set and here the default value
is selected for each new row.