Stores have a daily limit of 3 receipts per retailer, per transaction date.
For example, if you have already uploaded 3 Walmart receipts that all have the same transaction date of 30 June 2021, you will not be able to upload more Walmart receipts dated 30 June 2021.
It does not matter when you upload the receipt.
Unfortunately you will not be able to remove the limits for these stores.