One thing I did to fix this was just downgrade to a version before 5.0.8. as a temporary fix until the fix is resolved in the latest version.
Also another trick I have found is that when you’re creating the field in 5.0.8, make sure your image preview size is set to thumbnail and that the actual image you’re trying to set for that field is bigger than the thumbnail size. Don’t ask why that works too cause I have no idea.
Hope that helps!
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