Check your connection
Popurise saves on a short debounce. A weak connection drops the request. The save banner shows the status. If it says Reconnecting, give it a minute.
Check you are still signed in
Long idle sessions can be signed out by your IT policy. Reload the page. If you are sent to the sign-in screen, your session expired.
Hard reload
Press Ctrl+Shift+R on Windows or Cmd+Shift+R on Mac. The dirty state in the tab is rebuilt from the latest server snapshot.
Still stuck
Email dan@popurise.com with the scenario name and a screenshot of the save banner.