Use Holoviz Panel Dropdown value to query dataframe

I am trying to use a Holoviz Panel dropdown widget value to query a dataframe. The dataframe however does not reflect the change in the dropdown value. I added a markdown widget to check if the change in the dropdown value is being captured - It seems to be. However, I can't figure out how to update the dataframe. I am a complete beginner to programming, just trying to learn. Any help is appreciated.

import pandas as pd
import panel as pn
pn.extension()

# Dataframe

df = pd.DataFrame({'CcyPair':['EUR/USD', 'AUD/USD' ,'USD/JPY'], 
                   'Requester':['Client1', 'Client2' ,'Client3'],
                  'Provider':['LP1', 'LP2' ,'LP3']})

# Dropdown

a2 = pn.widgets.Select(options=list(df.Provider.unique()))

# Query dataframe based on value in Provider dropdown

def query(x=a2):
    y = pn.widgets.DataFrame(df[(df.Provider==x)])
    return y

# Test Markdown Panel to check if the dropdown change returns value

s = pn.pane.Markdown(object='')

# Register watcher and define callback

w = a2.param.watch(callback, ['value'], onlychanged=False)

def callback(*events):
    print(events)
    for event in events:
        if event.name == 'value':
            df1 = query(event.new)
            s.object = event.new

# Display Output

pn.Column(query, s)

Output Image