If I disabled ACF and refreshed the image edit page, the issue persists.
I have tried the same thing but the issue does not persist for me. I am positive that it is related to acf. The NaN error happens only when the advanced custom fields plugin is installed. It seems that the default WordPress edit crop is working fine.
If you remove the &image-editor at the end of the url, the NaN error is gone. Can you take a further look at this please?
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