Hello,
Thank you for reporting the issues with the new XAMPP with PHP 8.0.0 product. We reproduced the issue with the Apache syntax regarding php8_module and we are working on fixing it and releasing a new revision. This is only affecting the portable version.
You can get more information on this, and how to fix it until the new revision is released in the next post (thank you Altrea!)
viewtopic.php?f=16&t=80105#p270731
I'll update this thread when the new release has finished.