Strange behaviour in getClientRects()

[sandzone]

Attach (recommended) or Link to PDF file here:

https://www.tcs.com/content/dam/tcs/investor-relations/financial-statements/2023-24/q1/Management%20Commentary/Transcript%20of%20the%20Q1%202023-24%20Earnings%20Conference%20Call%20held%20on%20July%2012,%202023.pdf

Configuration:

• Firefox 117.0.01
• Kubuntu 22.1
• PDF.js version: 3.6.172 and later versions
• Built-in pdf viewer of firefox as well as using pdfjs-dist

Steps to reproduce the problem:

1. Select a region of text in the PDF in the link.
2. In certain selections, all the rectangles are not returned when using window.getSelection().getRangeAt(0).getClientRects()
3. Strangely, toString() returns the entire selected text. Also, isPointInRange() for missed elements is True!

What is the expected behavior and What went wrong? (add screenshot)