Reports and complaints have surfaced online from Google Photos users have found some of their older pictures to be "corrupted," as old physical photos would be at times. People have started to notice their years-old photos (over five years or so) have lines and deep cracks running through them, or they get blurry or distored in some areas. White dots seem to be the most common issue. But some photos seem to be more distorted than others. The issues is showing up everwhere from Android, iOS, to web versions of the app.
The corruption seems to persist when downloading the image, whether with individual downloads or using Google Takeout. Original copies don't seem to be impacted, but the edited ones are what show up in the Google Photos apps. Hopefully, Google pays attention to the issue and the complaints and fixes whatever the problem might be.