How can I avoid duplicate sales receipt numbers?

I am using Quickbooks Online Simple Start. I have connected my Squarespace store to my account and orders from Squarespace are imported as sales receipts. I have toggled on Automatic Invoice Numbers. I also have Quickbooks Online Payments set ups for when I make sales in person.

The issue I'm having is that Quickbooks keeps assigning duplicate sales receipt numbers and there appears to be no way to fix this once it's happened.

Example: I make an in-person sale and take the payment using Quickbooks online payments. The last sales receipt I recorded was #34, so this transaction will now be #35. Next, I make a sale through Squarespace. Squarespace assigns transaction #35 because the last transaction was #34 in Squarespace. Therefore, it gets imported into Quickbooks as sales receipt #35. So now there are 2 different sales, both with the same receipt number. Quickbooks in its infinite wisdom assumes that they are the same thing even though none of the other details match. So even though I can see that a transaction was imported from Squarespace with the correct details, the income isn't recorded correctly because it's been linked to the other sale that had #35.

The only workaround I have found is that every time I make a sale in person, I have to go into my Squarespace account and manually set the next transaction number so it's one larger than the last in person sale I made. But this is obviously not sustainable. 

I've disconnected and reconnected Squarespace, tried toggling on or off the automatic invoice number assignment. Nothing helps. I really don't want to have to start over with a new accounting software but if I can't resolve this issue then Quickbooks won't work for me.