Hi,
After testing, if you use the `record fields change` trigger, it will not be triggered when the record is created for the first time. It will only be triggered when the record is changed.
If the record has been created, but the associated field is not initialized, this will also be triggered when you assign the associated field for the first time.
For example:
1. The parentcontactid is initialized when the lead is first created, and the workflow will not be triggered.
2. The lead has been created, and the first time the parentcontactid is initialized, the workflow will be triggered.
If this helped you, I'd appreciate it if you'd mark this as a Verified Answer, which may in turn help others as well.
Best Regards,
Frank Gong