Seaborn kdeplot cumulative not rising to 1 when split by hue

Solution for Seaborn kdeplot cumulative not rising to 1 when split by hue
is Given Below:

Trying to use the sns.kdeplot() and keep running into an issue where the cumulative doesnt rise to one. This seems to predominantly occur when there is a large imbalance in the categories.

Any ideas what might be causing the normalization to not work as intended?

Example:

Create Sample Data

import pandas as pd # 1.1.0
import numpy as np # 1.18.1
import seaborn as sns # 0.11.1

np.random.seed(42)
sim_data = [[x,np.random.random(),'A' if x < 250 else 'B'] for x in np.arange(0,1000000)]
sim_data = pd.DataFrame(sim_data,columns=['Index','Value','Category'])

Plot Split by Hue (Left Hand Chart)

sns.kdeplot(
  data=sim_data,
  x='Value',
  hue="Category",
  common_norm=False,
  common_grid=True,
  cumulative=True
)

Plot Split by Hue Single Category (Right Hand Chart)

sns.kdeplot(
  data=sim_data[sim_data['Category']=='A'],
  x='Value',
  hue="Category",
  common_norm=False,
  common_grid=True,
  cumulative=True
)

Cumulative Distribution Charts with varying number of Categories

Changing the common_grid = True to common_grid = False seems to resolve above.

Thanks @Trenton