Attach (recommended) or Link to PDF file here:
[Scan-to-Mail-PDF1_(1).pdf](https://github.com/mozilla/pdf.js/files/6876708/Scan-to-Mail-PDF1_.1.pdf)

Configuration:
- Web browser and its version: Firefox Developer 91.0b7 (64-Bit)
- Operating system and its version: Windows 10 (21H1)
- PDF.js version: 2.10.339 (also tested with the online demo, Version 2.11.5)
- Is a browser extension:

Steps to reproduce the problem:
1. Open the attached pdf
2. Scroll to page 3

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/7944797/126957487-cc7a2d19-adfb-42e4-9809-74e1a7a85048.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/7944797/126957351-29aebb4d-eadd-4273-b69d-530b9060c12c.png)




*/
/**
 * Structure tree node. The root node will have a role "Root".
 *
 * @typedef {Object} StructTreeNode
 * @property {Array<StructTreeNode | StructTreeContent>} children - Array of
 *   {@link StructTreeNode} and {@link StructTreeContent} objects.
 * @property {string} role - element's role, already mapped if a role map exists
 * in the PDF.
 */
/**
 * Structure tree content.
 *
 * @typedef {Object} StructTreeContent
 * @property {string} type - either "content" for page and stream structure
 *   elements or "object" for object references.
 * @property {string} id - unique id that will map to the text layer.
 */
/**
 * PDF page operator list.
 *
 * @typedef {Object} PDFOperatorList
 * @property {Array<number>} fnArray - Array containing the operator functions.
 * @property {Array<any>} argsArray - Array containing the arguments of the
 *   functions.
 */
/**
 * Proxy to a `PDFPage` in the worker thread.
 */
class PDFPageProxy {