* What genre?
* By "hanging" do you mean just a cliffhanger where there's no full resolution of the conflict, or like the book ends abruptly with no semblance of a climax or conclusion?
* Are these self-published books? How many other books do the authors have?
Things that come to mind: Cliffhangers are more acceptable in some genres than others. Aside from a genuine cliffhanger, self-published authors often rush through the ending, where they just want to get the book done, and the conclusion ends up being very unsatisfying because they're just not very good at finishing that arc in a way that hits the expected beats for the genre (I've done this, unfortunately).
Having said that it HAS been an issue that authors' books are pirated and republished under a different name, with different covers, and identical contents. I have heard of instances of these scammers taking a long full length book and splitting it into two, republishing the pirated copy as multiple installments. I sort of doubt this is what happened here since I don't know why they'd have book two on preorder in that case (vs just publishing it for someone to buy right away), but who knows.
Teleport: Joshua T. Calvert
SOLAR STORM: Moon Base Delta Gerald M. Kilby
New genre for me. Space hard sci-fi, Well teleport was more just sci-fi.
All authors have many other books.
Correction: Summer's End was not a series, but it was clear this was written as a book 1. This book has publisher.
Looks like two of the three are "self-published". Well do you call it "self-published" if you own the publisher? I would.
The endings where professional, not cliffhangers, but just wanting for more.
Looks like I make a mistake with the first one, but three times in a row I sat down expecting to read a book that I can't.
For all I know all three of you are on HN... Yiks, As I am writing this I am know I am going to be shamed into buying the pre-orders.
Why do you think these authors are all on HN or that you'll be shamed into buying anything? That seems like a kind of oddly pessimistic outlook; I doubt anyone here is that invested in what books you buy.