Update all graphs dependent on one same dataframe when dataframe is filtered

Panel
1

In my app I have several graphs based on the same dataframe. I need to filter that df according to date and when I filter, all my graphs must be rendered with filtered data. My code is:

date_range = pn.widgets.DateRangeSlider(name='Date Range', start=data["date"].iloc[0], end=data["date"].iloc[-1], step=1*1*1)

# Trend Graph for Dampers
@pn.depends(date_range)
def update_df(x):
    
    df_filtered = data[(data['date'] > date_range.value[0]) & (data['date'] < date_range.value[1])]
    return df_filtered

get_dataframe = pn.bind(update_df, date_range)

filtered_df = get_dataframe()

# Trend Graph for dT
def plot_scatter1( selected_col_for_x, selected_col_for_y):

    tagname_in_db_forX = definition_dict[selected_col_for_x]
    tagname_in_db_forY = definition_dict[selected_col_for_y]
    
    hover = HoverTool(
                        tooltips=[
                            (selected_col_for_x,"$x{0.0}"),
                            (selected_col_for_y,"$y{0.0}")
                        ], 
                        formatters={
                        selected_col_for_x: "printf",
                        selected_col_for_y: "printf"
                        },
                        mode='vline'
                        )

    graph =  filtered_df.hvplot(x = tagname_in_db_forX, y=tagname_in_db_forY, xlabel=selected_col_for_x, ylabel=selected_col_for_y, kind="scatter", shared_axes=False, line_width=2, tools=[hover])
    
    return graph

# Trend Graph for dT
def plot_trend4( selected_col):

    tagname_in_db = definition_dict[selected_col]
    
    hover = HoverTool(
                        tooltips=[
                            ('cihaz_ismi', cihaz_ismi),
                            ('Zaman', "@date{%Y-%m-%d %H:%M}"),
                            (selected_col,"$y{0.0}")
                        ], 
                        formatters={
                        "@date": "datetime",
                        selected_col: "printf"
                        },
                        mode='vline'
                        )

    graph4 =  filtered_df.hvplot(x = 'date', by='_measurement', y=tagname_in_db, xlabel='Zaman', ylabel='', shared_axes=False, line_width=2, tools=[hover])
    
    return graph4

graph4=plot_trend4('Sisteme Kazandırılan Fark Sıcaklık')
graph5=plot_trend4('Fan Frekansı')
graph6=plot_trend4('Toplam Debi')
scatter1=pn.pane.HoloViews(plot_scatter1('Toplam Debi','Sisteme Kazandırılan Fark Sıcaklık'), backend='bokeh', sizing_mode="stretch_width", height=300)

This code only works at startup , later on, it does not reflect any update on graphs. And date_range slider acts a bit strage too. It moves both handles together. So I need help here. Thanks in advance.