Now PHP-8.2.9 opendir() and readdir() work OK.

I opened localhost Win10 Pro IIS my sites. But all my changes for access to "DataDir" did not give results. It was insufficient "Authenticated Users" in Permission Dialog under Security tab for "DataDir" on the site.

I renamed "DataDir_P" (in Win10) and created "DataDir" as new with default Win10 settings. The Data Files copyed from "DataDir_P".

Then I made restart all sites (by IIS Win10) on the localhost. I can read now list of files in "DataDir" with PHP.