Outlook crashes when opening emails and clicking inside Reading Pane

Microsoft 365 Apps for Business, 64-Bit

Version 2409, Build 18025.20140 Click-to-Run

My Outlook crashes whenever I

• double click a message to open it;
• select the message and press 'Enter' to open it,
• click inside the Reading Pane of a selected message, or
• double click a file of the Outlook item filetype (.msg) - please note the previewer error inside file explorer pasted at the end of this post.

To diagnose and fix, I have attempted:

- Repair install

- Uninstall and reinstall using using both the online and offline install methods and the custom configuration creator for Office

- Running the Microsoft Support and Recovery assistance tool

- Repaired inbox via scanpst.exe

- deleted Roamcache and all OST/PST/NST files and rebuilt the inbox

- turned off all add-ins

- turned off anti-virus

- uninstalled MS2Edge Runtime

- opened Outlook in Safe Mode

- opened Outlook after a "clean boot," turning off all non-MS processes and disabling all startup programs

- unchecked all the protective options inside Trust Center Settings

- made a new Outlook profile

- reduced Inbox size

- verified %appdata% is not mapped to a network location

What is exceptionally strange is that if a forward or reply is initiated using the embedded toolbar above the email in the Reading Pane and then the draft is popped out to its own window, then the email contents can be clicked, selected, copied, etc. However, if clicking anywhere inside the email Reading Pane prior to the reply/pop-out workaround, Outlook goes "not responding" and crashed. 

I am convinced that there is some handler error or handoff process or function call or read/write disconnect client side that is causing this failure.

The Inbox can be scrolled through and messages can be single-clicked and dragged to sub-folders without issue. Send/receive works just fine and connection to the exchange server is rock solid. 

If there was a solution posted previously on these forums, I've tried it and been unsuccessful thus far. Please help.