It’s a fresh install of Windows 10: Windows Photos doesn’t show HEIC files, in spite of having installed Microsoft HEIF Image Extensions. This fact is all over the Internet, including here: GitHub - brookmiles/windows-heic-thumbnails: Enable Windows Explorer to display thumbnails for HEIC/HEIF files
It only starts if you install some other software: either GitHub - brookmiles/windows-heic-thumbnails: Enable Windows Explorer to display thumbnails for HEIC/HEIF files or buy the HEVC video extension from the Ms Store Market.