If you have files that require different settings, like, for example, a group in Spanish and another in English, or if each group requires a different purchase order, ensure you separate them into different groups/batches.
If you are using AST-Link 2.x for Windows, or AST-Link G2.x for Mac, you can upload the first group, change the settings, and then upload the second group.
For AST-Link 1.x for Windows, or AST-Link AppleScript for the Mac, you'll need to wait until all submissions from the first group/batch are uploaded before changing the relevant settings. Then change the settings, select the new group of files for upload, and proceed.
You can confirm if a group or batch has been ingested when all submissions show on the Status of Submissions page, in your CaptionSync account.