Thunderbird has never polled the mail server for the contents of the junk/spam or trash/deleted folders by default when checking for new mail. They are polled when you select them for viewing. If you want them checked, right click the folders, select properties and select for them to be included when Thunderbird check for new mail. While you are there, I suggest you click the repair button to rebuild the index of mail. For a long time now folk with aggressive antivirus products have had issues with mail indexes being corrupted by scanning while they are in use. Sort of why their is a repair option in there really.

Matt, thank you for the response, however, I believe you misunderstand what my issue is. I don't need to check the trash folders from the IMAP server looking for new mail by default. I want to be able to see the trashed/deleted messages within Thunderbird when I delete the messages from within Thunderbird. As it stands now when I delete a message in Thunderbird it just disappears even though I have it set to route the deleted messages to the Trash bin. And my Trash bin indicates I have messages in it, but doesn't display them (see my original screenshot).

I have also hit the Repair button more times than I can count but I have no idea if it is doing anything. As I indicated I am not running any Antivirus software outside of Windows Defender. Plus none of what I am experiencing explains why the other account operates correctly.

Incidentally since I originally posted I completely uninstalled and then reinstalled Thunderbird with the same results.