core data not saving when I want to

I'm developing an app that saves medical records. I'm using core data with a single context and a single physical store. Despite calling the [managedObjectContext save:&error], if I extract the container via Xcode, the sqlite db doesn't show the most recent data.

Tried something like suggested here: Core data not saving my data , but didn't work out for me. To make things worse, data DO show up after a while: app can send sqlite via FTP to dump data for disaster recovery. It happens that last week worth of work doesn't always show up, but a week later is usually present.

What I fail to understand is: does [managedObjectContext save:&error] writes data IMMEDIATELY on the physical store? (my guess would be NO) How can I tell core data I want my data written down on the spot (provided it's actually possible)? Does closing the app and/or reboot the device make core data write to sqlite?

edit 1 - adding some code The [managedObjectContext save:&error] is called whithin the [CommonHelper SaveData:true]; just at the beginning of the @try block.

_FollowUp.bMI=[NSNumber numberWithFloat: [TextBMI.text floatValue]];
    _FollowUp.karfnosky=[NSNumber numberWithInt: [TextKarfnosky.text intValue]];
    _FollowUp.charlson=[NSNumber numberWithInt: [TextCharlson.text intValue]];
    _FollowUp.alimentazione=ButtonAlimentazione.titleLabel.text;
    _FollowUp.farmaci=TextFarmaci.text;
    _FollowUp.dolore=ButtonDolore.titleLabel.text;


    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];


    @try {
        [CommonHelper SaveData:true];            


        UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@“Data saved” message: @“Record saved successfully” delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alert show];


        float height = self.view.bounds.size.height;
        float width = self.view.bounds.size.width;
        lblSincro = [[UILabel alloc]initWithFrame:CGRectMake(width/2-200 ,height/2+30, 400, 20)];
        lblSincro.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        lblSincro.font = [UIFont boldSystemFontOfSize:16.0f];
        lblSincro.numberOfLines = 1;
        [lblSincro setTextAlignment:NSTextAlignmentCenter];
        lblSincro.backgroundColor = [UIColor clearColor];
        lblSincro.textColor = [UIColor whiteColor];
        lblSincro.text = @"Uploading in progress";

        UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge] ;
        spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge] ;
        spinner.frame = CGRectMake(0, 0,  width,height);
        spinner.tag = 3;
        UIColor *color = [[UIColor alloc] initWithRed:0.0 green:0.0 blue:0.0 alpha:0.5];
        spinner.backgroundColor =color;

        lblSincroDet = [[UILabel alloc]initWithFrame:CGRectMake(width/2-200 ,height/2+70, 400, 20)];
        lblSincroDet.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        lblSincroDet.font = [UIFont boldSystemFontOfSize:16.0f];
        lblSincroDet.numberOfLines = 1;
        [lblSincroDet setTextAlignment:NSTextAlignmentCenter];
        lblSincroDet.backgroundColor = [UIColor clearColor];
        lblSincroDet.textColor = [UIColor whiteColor];

        [self.view addSubview:lblSincro];
        [self.view addSubview:lblSincroDet];
        [self.view addSubview:spinner];

        [spinner addSubview:lblSincro];
        [spinner addSubview:lblSincroDet];

        [spinner startAnimating];

        dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){

            SyncHelper *sync=[SyncHelper alloc];
            BOOL result=sync.Sincronize;

            dispatch_async(dispatch_get_main_queue(), ^(void){
                [spinner stopAnimating];
                [lblSincro removeFromSuperview];
                [lblSincroDet removeFromSuperview];

                [lblSincro removeFromSuperview];
                if(result){
                    _SaveView  = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"successSincro", @"") message:NSLocalizedString(@"successSincroMessage", @"") delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
                    [_SaveView show];
                }else{
                    _SaveView = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"failedSincro", @"") message:NSLocalizedString(@"failedSincroMessage", @"")
                                                          delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
                    [_SaveView show];
                }
            });
        });
        _FollowUpLoad=_FollowUp;
        _isNew=false;
    }@catch (NSException *ex)
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message: @“Failed to save data” delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alert show];
    }

CoreData uses Write-Ahead Logging by default so the .sqlite file won't always contain all your data unless you disable this.

Like so...

NSDictionary *options = @{
     NSMigratePersistentStoresAutomaticallyOption : @YES,
     NSInferMappingModelAutomaticallyOption : @YES,
     NSSQLitePragmasOption: @{@"journal_mode": @"DELETE"}
};
[persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]