in ubuntu 22.04, Eclipse IDE for Enterprise Java and Web Developers (includes Incubating components) Version: 2024-09 (4.33.0), Under java perspective, in .java area, when I press ctrl+F, the search screen show and allow to input the search text, but the search inputbox collapsed and change to a white area quickly.
Quoting a reply from where you asked this elsewhere, "Eclipse 2024-12 will be released soon. If you're willing to test a developer build, you could take a look at https://www.eclipse.org/downloads/packages/release/2024-12/rc1 to see if the problem still occurs there."
If it still a problem, you can disable the new find/replace overlay from the "Text Editors" preference page and open an issue at https://github.com/eclipse-platform/eclipse.platform.ui/issues.