Table cell misalignment and table getting wider when moving the mouse over it with flex layout

Describe your context
Here's my setup:

python --version
Python 3.7.5

conda list dash
# Name                    Version
dash                      1.4.1
dash-core-components      1.3.1
dash-html-components      1.0.1
dash-renderer             1.1.2
dash-table                4.4.1

• OS: Windows 7
• Browsers:
  • Chrome 77.0.3865.75
  • IE 11.0.9600.19504

Describe the bug
Consider there following piece of code:

import os

import dash
import dash_html_components as html
import dash_table
import pandas as pd

df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/solar.csv')

app = dash.Dash(__name__)

app.layout = html.Div(
    children=[
        dash_table.DataTable(
            id='table',
            columns=[{'name': c, 'id': c} for c in df.columns],
            fixed_rows=dict(headers=True, data=0),
            data=df.to_dict('records')
        )
    ],
    className='eight columns',
    style={'display': 'flex', 'justify-content': 'center'})

if __name__ == '__main__':
    app.run_server(debug=True)

Now we have two problems:

1. The browser renders the table with a misalignment between header and the rest of the table, see screenshots below
2. When I start moving my mouse over the table then every time the mouse pointer crosses any of the cell boundaries then the table gets a few pixels wider (in Chrome) or smaller (in IE), see screenshots below.

Expected behavior

1. There should be no misalignment between header and the rest of the table
2. The mouse moving over the table should have no effect whatsoever.

Screenshots
Initial state in Chrome:

After having moved the mouse over the table for a bit:

Initial state in IE:

After having moved the mouse over the table for a bit:

提供された Python Dash DataTable の例を使用し、flex レイアウトと固定ヘッダー行で問題を再現します。Chrome と IE でセルの境界をまたいでポインターを移動しながら、ヘッダーとボディの位置合わせ、およびテーブル幅を確認します。ヘッダーの位置が揃ったままになり、マウスの移動によってテーブル幅が変化しなくなれば完了です。