Why doesn’t your crawler scrape some latest reviews?
Reviews posted on sites such as Amazon take time to show up on Amazon.com and will show up within 72 hours of posting in some cases.
Some reviews take a little longer to be posted, sometimes up to 4 or 5 days.
It is completely up to Amazon on how long (or even if) it will take for a review to be posted.
Also, please note that Amazon has the right to remove any review if it breaks their community guidelines or is marked as abusive.
Here is an illustrative example:
Anna scraped all reviews from Amazom.com for May 2021 on June 01 and reviewed the data on June 15, 2021.
Anna might probably miss some reviews posted on May 30 and 31.
P.S Amazon has limited the number of reviews available from their platform to 80 reviews per product.