If you press the “stop” button and the parking session remains active, it may be due to several reasons:
If you are in Majadahonda or Béjar, you won’t be able to stop a parking session once it has started. This is not an app error — it’s how those cities have organized parking times.
If you are not in one of those two cities, it may be because the ticket hasn’t reached the minimum time allowed per ticket. (Just as many cities have a maximum allowed per ticket, they can also set a mandatory minimum.) When you press “stop,” the ticket will adjust to the minimum allowed and will end once that time has passed.
Finally, another reason the app may not allow you to stop a ticket is if you are outside regulated hours; during this time, you cannot make changes to your active tickets.