Scary stuff, this is! It seems that some of the brilliant reviews you get for your published books can, like, disappear! And the culprit is the robotic algorithms of the Amazon machine. Here is an article that gave me first the shivers--and then armed me with some ideas on how to avoid/defend against the Black Hole of reviews.

How to Avoid It!

For example, if you want to encourage people to buy your book (you bet!) and to review it afterwards (sure thing!), then avoid using links to your book that identify you. Amazon, in its wisdom, attaches all kinds of identifiers to anything you search on your computer. It knows this is YOU searching. So you need to remove that extra coding.

Here is a live example:

When I look up my book on Amazon using my computer, I get this LOOONG code in the URL box:

https://www.amazon.com/dp/B07F8CMBM4?_encoding=UTF8&isInIframe=1&n=1331401&ref_=dp_proddesc_0&s=digital-text&showDetailProductDesc=1#iframe-wrapper

This not only identifies my book, but identifies that the link came from MY computer. Amazon can then track any sales or reviews that come from anyone using that link. Which means it MAY think that the purchase or review has been coerced or encouraged by me (well, sure it has!) and they may remove that review, thinking it is biased.

But, hey, aren't we supposed to seek reviews? Ask buyers to give an honest review of the book?  Sure, but NOT if the link they use points back to the author's computer!

To strip the coding to JUST your book, remove everything after the book number, starting with the "?" like this stripped from the code listed above:

https://www.amazon.com/dp/B07F8CMBM4

Now your readers can click to get your book without the link identifying you. When they then review it, Amazon will see this as NOT coming through you, but as an organic (natural, not coerced) purchase and will accept the review that way as well. 

Now you know--start stripping that URL code.