iphone videos transferred to W10 no longer have thumbnail images nor video properties.

You can remove that tag from all .mov movies in that folder with a command like:

exiftool -m -P -overwrite_original -api LargeFileSupport=1 -ext mov '-Keys:FullFrameRatePlaybackIntent=' .

But first do a test and see if it helps. That tag seems to take effect to movies with ≈85 fps or more in Sequoia QuickTime Player but its mere presence seems to currently confuse Windows. You can add that tag back with:

exiftool -m -P -overwrite_original -api LargeFileSupport=1 '-Keys:FullFrameRatePlaybackIntent=1' movie.mov

You can check the related tags with:

exiftool -a -G1 -s -n -fileOrder5 FileName -FullFrameRatePlaybackIntent -VideoFrameRate .

Or check almost all tags with:

exiftool -a -G1 -s -n -fileOrder5 FileName -api QuickTimeUTC=1 .

exiftool can be downloaded freely for various operating systems from (I have used MacOS package .pkg because it is easiest to install):

https://exiftool.org/

Try if removing FullFrameRatePlaybackIntent tag from the movie helps. It is a key that iOS/iPadOS 18 introduced. It represents whether a high frame rate movie should play at full frame rate or not. It seems Windows does not currently properly read that tag.

High frame rate playback option in iOS/iP… - Apple Community

GranAlcazar wrote:

In addition to my earlier message I installed exiftool for windows but when I type this in the command line

exiftool -m -P -overwrite_original '-Keys:FullFrameRatePlaybackIntent=' output.mov

I get

Error : File not found - '-Keys:FullFrameRatePlaybackIntent='

Oh, just remove all those single quotes because that command does not need quotes at all:

exiftool -m -P -overwrite_original -api LargeFileSupport=1 -ext mov -Keys:FullFrameRatePlaybackIntent= .

(Mac and Linux use single quotes ' but Windows uses double quotes " . Some commands might need both mixed in a certain way. Some word processors are eager to use and replace curly quotes ” which do not work.)

And on Windows use CMD shell because PowerShell has issues with some commands.

https://exiftool.org/forum/index.php?topic=8137.0

Sometimes it might be dangerous to use wildcards so I used "-ext mov" in the command so only .mov files in that folder are processed and files with other suffixes are left intact (or use "ext mov -ext mp4" to process those two file types. "--ext mp4" would mean that all files except .mp4 are processed). The period "." at the end of the command means "this folder" so the user does not need to give file names. At least on the Mac Terminal it works that way and your command does essentially the same.

I used quotes when initially testing this and forgot to remove them when done. Anyway I am glad you got it working.