Configuration is delivered over the station's live connection, so an offline station won't apply anything until it reconnects. Check the station's connection badge first.
While the change is pending, the page shows "Saved. Waiting for the station to report that it has applied this."
If the station is online but still stuck, use Restart app. The app re-reads its configuration when it starts. You can also check the station log for the configuration delivery and the station's response.