Error
Business Validation Error: A project is already using this name. Please use a different name.
Cause
Project was originally created in QuickBooks Online. When attempting to batch the job, QuickBooks Online tries to map this as a sub customer. Since a project already exists with the same name, QuickBooks Online presents an error since you cannot duplicate names across all records
Resolution
This can sometimes be caused by a mapping issue. Please review the following articles to resolve any possible issue relating to job mappings.
Projects should be created in Connectwise PSA using the above article and batched to QuickBooks Online. Once the invoices are batched to QuickBooks Online, navigate to Projects, click the down arrow next to "Create New Project" and click convert from Sub-Customer. The project should map without an issue moving forward.
If the project is already existing, rename the project temporarily. Batch the invoices using the correct project name and convert the sub-customer to the project. Change the original project name to match the project you just converted. You will be prompted to merge the 2 records. Approve the merge request. Your projects should batch without issues moving forward.