Fixed column scroll is broken on 6.5.2, with Material UI 6


The fixed columns are scrolling horizontally. CodeSanbox link: https://codesandbox.io/p/sandbox/material-table-starter-template-forked-s45g2z


**Screenshots**
<img width="788" height="518" alt="Image" src="https://github.com/user-attachments/assets/38003edd-909f-4c29-b688-d2bcb3b2a419" />

**Desktop**

- OS: macOS 26.2
- Browser: Chrome
