Unable to remove temporary SMTP address of group (original address not added)

[Arne-RFA]

After setting up two DL to test with, and synced them to 365 ran the multiple migration and it all looked good until the below (same error in both tests)

[6/6/2024 12:22:12 PM] - =====
[6/6/2024 12:22:12 PM] - Post Create Errors:
[6/6/2024 12:22:12 PM] - Primary Email Address or UPN: [email protected]
[6/6/2024 12:22:12 PM] - External Directory Object ID: ed02fdad-7d89-4917-b29b-5c8ae144d686
[6/6/2024 12:22:12 PM] - Name: zzzDLtest1
[6/6/2024 12:22:12 PM] - Alias: zzzDLtest1
[6/6/2024 12:22:12 PM] - Attribute in Error: Unable to remove temporary SMTP address of group.
[6/6/2024 12:22:12 PM] - Error Message: Unable to remove20240606T12095141101728395316@clientpublicdomainTenant.onmicrosoft.com - manual removal required.
[6/6/2024 12:22:12 PM] - Error Message Details: ExC71195|Microsoft.Exchange.Data.DataValidationException|There is no primary SMTP address.
[6/6/2024 12:22:12 PM] - =====
[6/6/2024 12:22:12 PM] - =====
[6/6/2024 12:22:12 PM] - General Errors:
[6/6/2024 12:22:12 PM] - Error Message: Unable to locate a mail.onmicrosoft.com address either on premises or office 365.  This may indicated larger failures to set SMTP addresses.  Manual correction required and run enable-hybridMailFlowPostMigration to fix.
[6/6/2024 12:22:12 PM] - Error Message Detail: 
[6/6/2024 12:22:12 PM] - =====

The AADC Synced DL have been "replaced" with cloud only DL, but only have the "temporary" SMTP addresses on them

Within AD it shows as

Happy to send over the full logs, but cannot attach them here.