From the main menu in the upper left, select Settings.
Scroll to the bottom of the menu and click/tap "Delete Local Data". Your actual wine data will not be deleted, just the local browser cache.
Click "Confirm Delete" and wait for the page to reload and log you out.
Refresh your browser to ensure you have the latest version of PWC.
Log back in and your browser will perform a fresh sync of your data!
If you run into any issues doing the above and you are using the Chrome browser, you can paste the following into your Chrome browser and hit enter:
chrome://settings/cookies/detail?site=app.personalwinecurator.com
Then choose remove all (don't worry it won't delete your actual data). Return to personalwinecurator.com and log back in.