I'll provide some information as to why your expense report is showing duplicates. This will guide on how you can correct them, Dewalter

Before we start, may I know what specific reports did you use? Normally, the data that shows up on the report depends on the information you've entered in QuickBooks Online (QBO). Therefore, you'll want to make sure to select the correct Report period to ensure correct data appears in your end. I've provided a sample screenshot for visual guidance:

To give you more information on how you can filter reports specifically for your business needs, go through this article for more details: Customize Reports In QuickBooks Online.

Beyond that, some of our reports may only be available to certain subscription. In order to give you an idea what are these lists of reports, consider checking out this resource for future reference: Reports Included In Your QuickBooks Online Subscription.

Keep in touch if you have any other concerns when running reports. I'm only one post away if you need further assistance.