Import / Export CSV Custom

Version ie <v5.11.0>

Environment <Docker/Synology>

When exporting the customer list as a CSV, it can be read in Excel as a UTF-8 coded file. All 80 customers were exported without errors.
If the same CSV file is imported, customer entries are missing.
Repeated attempts show that the same entries are always missing.
No special features are recognizable. The customer data is rudimentary Name, street, city, country

Hi,

Is it possible the same name appears more than once? If you’re able to include an email address it may help.

Yes, a customer is duplicated with different content in other fields, but the name is the same.

I think the app is inserting the first client and then updating it for the second matching record.