This is a common problem due to TB's use of the Date header:

https://support.mozilla.org/en-US/questions/1158818

From https://blog.kamens.us/send-later/

IMAP Received Date: Although this add-on is not yet available for Thunderbird 78 [102], there is a workaround:

Open the Thunderbird Preferences[Settings]. Click on “Config Editor…” in the Advanced section of the General preferences [General/Indexing]. Enter “mailnews.customDBHeaders” (without the quotes) into the search box. If it’s not there, right-click in the search results area, select New > String, enter “mailnews.customDBHeaders” (without the quotes) as the preference name to create and click OK, and enter “Received” (without the quotes) as the value and click OK again.

If, on the other hand, “mailnews.customDBHeaders” shows up in the search results, then double-click on it to edit the value, enter a space and then “Received” (without the quotes) at the end of the value, and click OK.

Thanks for the quick reply. We went through these steps and attempted to repair his inbox, but the issue remains the same. I've attached an image of the change he made; please let me know if anything looks wrong. Otherwise, I'm going to have him test with a new profile.

The preference is correct. As I understand it, if you restart TB, then re-index by Repair Folder from the folder Properties menu, the Received column should show the correct date, even if the Date column is incorrect. Right-click any column button to enable columns. Unfortunately, I don't have any messages with malformed Date headers to test this method.