Three links in duckduckgo search: 

https://9to5mac.com/2024/09/18/ios-18-messages-app-crash/

https://www.zdnet.com/article/ios-18-is-bricking-some-ipads-heres-what-to-know-before-you-install-it/

https://www.zdnet.com/article/is-ios-18-tanking-your-iphone-battery-heres-why-and-what-you-can-do/