Is one good #Amazon review worse than no reviews?

I may have made a mistake recently. I had five novels out on Amazon but, as you would expect, the most recent ones were better than the first ones. I would hate to reach a point where my writing skills are not improving, but an unfortunate consequence is that my older books won't be as good as what I'm writing now. As I've been writing a series of novels which should be read in order, I decided to revamp the first novel.

This wasn't just a quick edit or tweak. Instead I took the first two books, extensively edited them and combined them into one 390+ page novel. It was then submitted to the proofreading and editing process and given shiny new front cover artwork. I am very pleased with the results, but the changes were too great to simply make it a new edition of book one.

So I removed the original book 1 and book 2 from sale and launched the new one as a new release (Astronomicon: The Beginning). As a side-effect I lost all my original reviews, but with renewed enthusiasm I tried to persuade readers to leave reviews and ratings of the revamped book.

My efforts were quickly rewarded with a good review (4 stars and some most positive comments) but that's when the problem started. As soon as the book had one review, sales all but stopped. At first I put it down to the usual random fluctuation in sales, but nothing improved. Even a string of good ratings on GoodReads.com  made no difference.

It's been suggested to me that having one good review makes potential readers suspicious. They often assume that I've reviewed my own novel, rendering one good review much worse than no reviews at all.

Has anyone else had similar experiences?