Folder incorrectly displays as document
Previously I'd complained about an issue where in Favourite Folders/Compact View some folders would display as document icons rather than folder icons, and also Thunderbird would display these at the top of the folder list rather than in alphanumeric order. This previously was fixed by the third and final procedure described [in support article 1370142:]
Unfortunately this behaviour is back in Thunderbird 102.5.1 on MacOS 12.6.1, and deleting files and folders as suggested no longer works. Before attempting this I have verified that (a) Favourite Folders view is disabled and (b) that none of the three affected folders are checked as favourites.
Thanks in advance for a fix and/or troubleshooting clues.