Patternfly has been upgraded to React 18.3, but React 19 warnings have not been resolved. 

Also update:

 {
   "compilerOptions": {
     "jsx": "react-jsx",         // from "react" (new transform)
   }
 }
 

See https://react.dev/blog/2024/04/25/react-19-upgrade-guide for more info and automated codemods. 

See react-19-readiness-assessment.md