Pinned Columns and Column Grouping Combination Causes Styling Issues

[kelvinsanchez15]

Duplicates

• I have searched the existing issues

Latest version

• I have tested the latest version

Steps to reproduce 🕹

Link to live example: https://codesandbox.io/s/nice-mendeleev-bnq08u?file=/demo.tsx:842-856

Steps:

1. Use pinned columns feature
2. Add Column grouping
3. Styling issue occurs

Current behavior 😯

Screenshot

Expected behavior 🤔

It should look closer to the attached screenshot but with a working Column grouping.

Screenshot

Context 🔦

No response

Your environment 🌎

npx @mui/envinfo

  Browser: Chrome

  Output from `npx @mui/envinfo` goes here.
   System:
    OS: Linux 5.15 Ubuntu 22.04.2 LTS 22.04.2 LTS (Jammy Jellyfish)
  Binaries:
    Node: 16.19.1 - ~/.nvm/versions/node/v16.19.1/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v16.19.1/bin/yarn
    npm: 8.19.3 - ~/.nvm/versions/node/v16.19.1/bin/npm
  Browsers:
    Chrome: Not Found
    Firefox: Not Found
  npmPackages:
    @emotion/react: ^11.10.6 => 11.10.6 
    @emotion/styled: ^11.10.6 => 11.10.6 
    @mui/base:  5.0.0-alpha.126 
    @mui/core-downloads-tracker:  5.12.1 
    @mui/icons-material: ^5.11.16 => 5.11.16 
    @mui/material: ^5.12.1 => 5.12.1 
    @mui/private-theming:  5.12.0 
    @mui/styled-engine:  5.12.0 
    @mui/system: ^5.12.1 => 5.12.1 
    @mui/types:  7.2.4 
    @mui/utils:  5.12.0 
    @mui/x-data-grid:  6.2.0 
    @mui/x-data-grid-pro: ^6.2.0 => 6.2.0 
    @mui/x-date-pickers:  6.2.0 
    @mui/x-date-pickers-pro: ^6.2.0 => 6.2.0 
    @mui/x-license-pro:  6.0.4 
    @types/react: ^18.0.37 => 18.0.37 
    react: 18.2.0 => 18.2.0 
    react-dom: 18.2.0 => 18.2.0 
    typescript: ^5.0.4 => 5.0.4 

Order ID or Support key 💳 (optional)

64675

[MBilalShafi]

Unfortunately, as of now, column pinning and column grouping don't perform great together. The good news is, the issue is already known and is in our backlog.
Here's the link to the original issue: #7041
Please feel free to continue the discussion or upvote the issue to move it up the prioritization order.

I am closing this one to avoid duplication.