dcc.Upload and wildcards compability


I need some helps regarding dcc.Upload and wildcard compability.

Currently Im trying to create mutliple Divs with an Upload Drag and Drop and select File method, which for some reason is not working.

The Layout:

dcc.Upload(id={'type':'upload_digGasSim_sensorCsv', 'index': x}, children=html.Div([
                           'Drag and Drop or',
                            html.A('upload csv', style={'flex': '30%'})
                        ]), style={'width': '100%',
                                  'height': '60px',
                                  'lineHeight': '60px',
                                  'borderWidth': '1px',
                                  'borderStyle': 'dashed',
                                  'borderRadius': '5px',
                                  'textAlign': 'center',
                                  'margin': '10px'
}) for x in range(0,10),

and the callback:

    Output('plc_gasDigCsv', 'children'),
    [Input({'type': 'upload_digGasSim_sensorCsv', 'index': ALL}, 'content')]
def saveDigSensorCsv(list_of_contents):
    #do some stuff here

what I ve noted so far:
the callback is fired when:
the server starts,
the site is reloaded,
the upload divs are generated.

looking at dash.context.triggered showed me that the divs all exist (array with None objects], and are linked to the callback, but whenever i select and upload a file, the callback doesnt react.

I ve done similiar things with dcc.Upload but just without wildcards usage

Thanks in adnvance!