Causes and solutions:
1. Network abnormalities: change to a different network and try again.
2. Insufficient storage space for Google Photos: empty your cloud storage space with the following methods:
a) Enter Google Drive, delete invalid files, and clean up the storage space.
b) Enter Google Photo> Library> Trash> Select Picture> Permanently Delete, release space.
c) Enter Google Photo> Avatar in the upper right corner> Account Sorage> Review and Delete to delete invalid files.
3. Expand Google storage space: go to Desktop> Google Drive> More in the upper left corner> Buy storage, and choose your preferred package. Note this is a paid addition.
If the issue persists, contact the Nothing Support Team for further assistance.