A fresh upload using the iOS app ended up in a sequence where one of the images is located at 0/0. All other images look fine. The problematic image: Mapillary
Incidently I saved this image and can inspect the exif data which look correct (GPS Latitude/Longitude pointing to a place in Berlin).
So it seems that at some point during the upload, either while processing the sequence in the app or later on the servers, something happened to the coordinates. Any ideas?
BTW, this is not the first time — I can provide more examples if needed. Or just look around in the same region…