add_at_risk_counts moves grid to the front when using seaborn

[krz]

Hi,

When I use the default seaborn theme, the grid is in the front. How can I move the white grid lines to the background.
For example:

import pandas as pd
import numpy as np
from lifelines import KaplanMeierFitter
from lifelines.plotting import add_at_risk_counts
import seaborn as sns

sns.set_theme()

# Generate random data for three hypothetical dataframes
np.random.seed(42)

def generate_data(size):
    return pd.DataFrame({
        'duration': np.random.exponential(10, size),
        'event': np.random.binomial(1, 0.5, size),
        'age': np.random.normal(50, 10, size)
    })

df1 = generate_data(100)
df2 = generate_data(100)
df3 = generate_data(100)

dataframes = [df1, df2, df3]

# Kaplan-Meier Estimation
kmf = KaplanMeierFitter()


fitters = [
    KaplanMeierFitter().fit(
        df['duration'],
        event_observed=df['event'],
        label=f'DataFrame {idx}'
    )
    for idx, df in enumerate(dataframes, 1)
]

for fitter in fitters:
    ax = fitter.plot()

add_at_risk_counts(*fitters, ax=ax)