Altair Barchart is blank, matplotlib equivalent shows correct visualization

I have been using altair for a time and this is the first time that I have experienced this issue, I have this simple code:

import pandas as pd
import altair as alt

# extract data into a nested list
data = {
        "Name of District": ["Kollam", "Beed", "Kalahandi", "West Medinipur", "Birbhum", "Howrah"],
        "No. of Cases": [19, 11, 42, 145, 199, 85],
    }

# create a dataframe from the extracted data
df = pd.DataFrame(
    data
)

# Display the first 5 rows
print(df.head().to_markdown(index=False, numalign="left", stralign="left"))

# Create a bar chart with `Name of District` on the x-axis and `No. of Cases` on the y-axis
chart = alt.Chart(df).mark_bar().encode(
    x='Name of District',
    y='No. of Cases',
    tooltip=['Name of District', 'No. of Cases']
).properties(
    title='Bar Chart of No. of Cases by Name of District'
).interactive()

# Save the chart
chart.save('no_of_cases_by_name_of_district_bar_chart.json')
display(chart)

it returns this plot:

If I plot it using matplotlib, then i get the correct plot:

I have tried this on colab and on my local machine and I have gotten the same results, why could this happen?

Altair requires that special characters be escaped in the column names. See documentation here.

This code should produce the plot you're looking for.

chart = alt.Chart(df).mark_bar(
).encode(
    x='Name of District',
    y='No\. of Cases',
    tooltip=['Name of District', 'No\. of Cases']
).properties(
    title='Bar Chart of No. of Cases by Name of District'
).interactive()