Mouse tracking in Firefox: `<pre>` `<code>` elements with multiple lines of code do not report text under the mouse properly.

[hwf1324]

Steps to reproduce:

1. Open: https://www.nvaccess.org/files/nvda/documentation/developerGuide.html
2. Mouse over a line of text in a code block

Actual behavior:

For most lines of text, mouseover text does not report text. Text is reported only when the mouse moves over a small area of the left border.

Expected behavior:

Report text on mouseover like in Chrome.

NVDA logs, crash dumps and other attachments:

System configuration

NVDA installed/portable/running from source:

install

NVDA version:

alpha-34198,67f6cb99（2025.1.0.34198）

Windows version:

Windows 11 Version 22H2 (OS Build 22621.4037)

Name and version of other software in use when reproducing the issue:

Firefox 131.0 (64 bit)

Other information about your system:

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

No

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Yes

[hwf1324]

CC: @jcsteh

[Adriani90]

Does this work in Chromium?

[hwf1324]

Does this work in Chromium?

Yes, as I said in the issue description, this works fine in Chrome.