Apologies, my fault, formerly copy these groups and pasted into another evensheet, then the names were changed automatically to not coincide with the originals.
But there must be a problem because they can not have the same name.
I had ordered all groups as follows:
AREA 15 ZONA 0
AREA 15 ZONA 1
At some point C2 has changed the name of this groups and now are as follows:
As you can see ... they are all the same !.
How is possible? C2 does not allow the same names in the groups.