You made changes in your repository i.e bitbucket repo and you noticed that your application did not get updated with the changes you made in your repository.
The behaviour for mirror service does the periodic sync every 5 minutes. If refreshRate in those config-server instances are 0 (default value). Having said this the client apps should get the updated properties in less than 10 mins.
But please note that config-server does not fetch the new repository commits automatically without client requests or manual syncing using the cf command i.e
cf config-server-sync-mirrors my-config-server
The behaviour of your application not being updated without a restart or manual sync is expected behaviour.
Please restart your application so that will be able to updated data from the changes you made in your repository.