When creating collection items, some images were inserted properly, while others were not. Surprisingly, no error was returned for the unsuccessful image uploads.
Try uploading that same image manually into the same CMS field you were trying to load it automatically and see if it works. If so, sounds like a network issue and you should message support.
Webflow is picky about image assets, including the 4MB limit, certain filename restrictions, type restrictions, and your CMS image field can have additional constraints such as dimensions. Any of these could cause it to be rejected.
As to the lack of an error, my guess is that media uploads happen asynchronously from the API call, so you had a successful call but the subsequent processing on that specific field could not complete.
and following is working
so name and size not issue.
is any specific criteria for image