I just found this but Microsoft answered September 16, 2024:
Hovering over a hyperlink in an email may not display embedded URL in a pop-up tooltip in new Outlook
Outlook on the web New Outlook for Windows
Last Updated: September 16, 2024
ISSUE
When you hover over a hyperlink in an email message, the embedded URL may not be displayed in a pop-up tooltip, while in some other cases it may work as expected.
STATUS: INVESTIGATING
The Outlook Team is investigating this issue for a fix. We will update this article when we know more about fix status.
WORKAROUND
You may switch back to classic Outlook for Windows (by turning off the ‘New Outlook’ switch near top right-hand corner) or use OWA (Outlook on the web) to access such emails, as it always displays embedded URL in a pop-up at the bottom left-hand corner of browser window (or ‘status bar’ at the bottom of a browser).
ADDITIONAL INFORMATION
This issue may occur for a regular URL, like http://www.microsoft.com or a URL embedded within text, like ‘link’ with embedded URL pointing to: http://www.microsoft.com.