I'm sure you already know, but I have to say it:
First, the problem of loading is the problem that really needs to be addressed. I am not sure where these images come from, if they are being generated incorrectly or why they are processed when they are partially loaded, but this is the problem that must be solved. Users have experienced long load times and can adequately prepare for that (load indicators, image placeholders, lower quality images that are replaced with high resolution, etc.), but images with medium load are unexpected, for what a user would not be necessarily ready to handle that.
Until I solve the real load problem, I would suggest that you simply report it as an error.
However, your application reports errors, would follow the same pattern and would show that some images could not be loaded. Provide the user with a way to activate a reload, preferably one that requests all the failed images so that they do not have to search and touch each failed image.
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