The 'Name of Record' record identifier (activity Id) matches the 'Invitation id'

If the Update action failed, because of Flow design work, it triggers mechanism of the Flow that cause the error. Basically, it will create a new record with the same id follows the upsert process as stated in the following documents.

And when a new record is upserted, due to having the same id as the previous invite record, this record will be detected as having duplicate key matching the ‘invitation id’ mentioned above.

Reference:

https://learn.microsoft.com/en-us/power-automate/dataverse/update

• https://learn.microsoft.com/en-us/power-apps/developer/data-platform/use-upsert-insert-update-record?tabs=webapi#understanding-the-upsert-process-for-standard-tables