I am working, not to say struggling, with an EPUB3 book exported from InDesign 2023.
The dedication page looks like this in Sigil:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US" xmlns:epub="http://www.idpf.org/2007/ops">
<head>
<title>Dedication</title>
<link href="css/idGeneratedStyles_0.css" rel="stylesheet" type="text/css"/>
<link href="css/idGeneratedStyles_1.css" rel="stylesheet" type="text/css"/>
</head>
<body id="dedication">
<p class="FRONT-MATTER_Dedication">To the hundreds of<br/>Southern Polytechnic State University <br/>
students who helped me refine<br/>my approach to this material,<br/>thank you! </p>
</body>
</html>
When I upload to Google Play Books and look at it with the Web book viewer, it looks like this:

The punctuation on the last two lines has been moved to the beginning of the line!
It looks right in Sigil, in the Google Play Books viewer for Android, and in Calibre, but I'm reluctant to just say "aberration" and forget about it. A little time with Google finds one similar case that appears to be confusion of dir="rtl". To test, I added dir="ltr" to the <p> element, and that fixed it. My question is why would I need to do that?
For the record, the CSS for FRONT-MATTER_Dedication looks like this:
p.FRONT-MATTER_Dedication {
-epub-hyphens: none;
color: #000000;
font-family: "Minion Pro", serif;
font-size: 1.333em;
font-style: italic;
font-variant: normal;
font-weight: normal;
line-height: 1.5;
margin-bottom: 9px;
margin-left: 0;
margin-right: 0;
margin-top: 126px;
orphans: 1;
page-break-after: auto;
page-break-before: auto;
text-align: center;
text-decoration: none;
text-indent: 0;
text-transform: none;
widows: 2;
}
It was generated by InDesign, so there's some useless stuff in there, but I can see nothing harmful.
<dc:language>ar-SA</dc:language>in the generated EPUB? There is no Arabic anywhere in the InDesign document. – Bob Brown Sep 11 '23 at 13:54https://www.accessiblepublishing.ca/working-with-indesign/#primary-lang
– granite Sep 11 '23 at 23:23