We are also experiencing this with remote notifications with typical 16:9 images. It's mostly un-noticeable with regular notification thumbnails, but we use the UNNotificationAttachmentOptionsThumbnailClippingRectKey with a CGRect that is different for each notification. The result is some notifications with extremely fuzzy or blurry thumbnail images on iOS 14, but the same notification thumbnail with the same cropping is clear on iOS 13, 12, etc. Long-pressing to expand the notification shows a clear image on any iOS version. This has been driving me a little crazy, but Unless there's some kind of build setting I don't know about, this seems to be a change in iOS 14 that is beyond my control. The difference is clear regardless of the original image size/resolution.