@Galgani, Stefano Welcome to Microsoft Q&A, thank you for posting your here!
The asterisk character
* is a valid character in a blob name. If the asterisk character is used in a prefix, then the prefix will match blobs with an asterisk in their names. The asterisk doesn't function as a wildcard character.
A prefix match string like container1/ applies to all blobs in the container named container1. A prefix match string of container1, without the trailing forward slash character (/), applies to all blobs in all containers where the container name begins with the string container1. The prefix will match containers named container11, container1234, container1ab, and so on.
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