Google Photos Favorites Missing or Not Syncing
Favourites that vanish or refuse to sync usually point at a second Google account, a paused backup or a photo that never left the phone. Check them in this order before assuming anything was deleted.

When Google Photos favorites are missing, first check whether the photographs are missing too. A picture that opens on your phone but cannot be found on the web needs a different fix from one that appears everywhere with its star switched off. Start with one recognizable image, then work through these checks from quickest to slowest.
02 · Favorites not syncing: verify the upload
In the phone app, open your profile picture > Photos settings > Backup. On iPhone, the settings entry may read Google Photos settings. Check the backup account and read the current status, such as Backup complete, Backup is off, or Waiting for Wi-Fi.
Then open the actual missing image and inspect its backup status. Use Back up or Back up now if offered, after confirming the destination account. Seeing a photograph in the mobile gallery does not prove that a cloud copy exists.
On Android, screenshots and downloaded images may live outside the camera folder. Under Backup, open Back up device folders and enable only the folders you want uploaded. An overall completed status does not establish that an excluded folder was included.
Google's Troubleshoot photos not backing up guide specifically recommends checking the account and device folders. Upload one missing item first, then look for that exact picture on the website before changing settings for the whole library.
04 · Check Trash before its recovery window closes
Open Collections > Trash in the mobile app. On the website, choose Trash from the navigation. Some regions call it Bin. Select the missing image and choose Restore, then reopen the photograph and check its star.
Google's Restore recently deleted photos & videos page gives two different windows: backed-up items remain in Trash for 60 days; items that were not backed up remain for 30 days. These are retention windows, not a promise that every missing image is recoverable. Emptying Trash or permanently deleting an item can remove the recovery option sooner.
A favorite is not protected from deletion. If you removed the photograph while clearing the library, its Favorites entry disappears with it. After restoration, verify the image appears on the web, then check Favorites again.
Also check the phone's own gallery trash or Apple Photos' Recently Deleted if you deleted a local copy there. These are separate places with their own behavior; a Google Photos restore cannot retrieve an item that exists only in another app's deletion history.
06 · Test the star, then improve retrieval
If the photograph is backed up under the same account and the star still disagrees, refresh the website, close and reopen the phone app, and install available app updates. Allow time for the change to arrive. Test one image again instead of un-starring your entire collection.
If it remains inconsistent, send feedback from Google Photos with your device model, app version, backup status, and whether the image itself appears on the web. Those details separate an upload problem from a Favorites display problem.
For screenshots you keep as information, a second retrieval route can help. Save the image yourself to dEssence through its web app or Telegram bot and add a phrase such as “blue cabinet measurements for the hallway.” Later, search by that description instead of remembering when you starred it. This is a separate saved copy, not a Google Photos connection or a way to restore deleted originals.