If parent customer has changed when updating the jobsite. QuickBooks Online will give a message indicating jobsite is not linked to the expected customer (with the customer name), do you want to relink?
To transfer this invoice to QuickBooks Online please unlink the jobsite and the parent customer and try linking them again.
Note: If you click Continue that invoice will not be synced or transferred over to your QuickBooks Online, you would have to unlink the parent customer and jobsite and then perform the sync.