You received this error while importing zone file using the CLI method to Azure DNS.
409 Client Error: Conflict for url: Zone file path
There is always a limit of records you can import to the Azure DNS zone. Let say MS set a limit of 2000 records and you try to import a file more than 2000 DNS records.
If you are importing more records than it shows in Azure DNS portal then you will getting this error when during the import, the records count reached the limit. Simply ask Microsoft to increase the records limit for each zone file.