Thunderbird 128.9.1esr (64-bit) [Linux Mint] retrieves messages from my 4 email accounts (2x gMail & 2x Yahoo-based). It then displays each email retrieved TWICE. In the past, Left-Clicking on Unified Inbox | Properties then the [Update] button would "single-up" the list into a 1-for-1 relationship. I then sort my mail MANUALLY into local folders or delete unwanted in order to keep my inbox "zero'd". After my recent Linux Mint 22.1 update, this no longer works and I need to close and re-open Thunderbird to get any "ghost" messages that I haven't sorted or deleted to disappear. I am sure that I have something configured incorrectly but I can't seem to find it. None of the 4 accounts is "aware of" or forwarding to or retrieving from any of the others - they are totally independent. Yet I get duplicated emails from all 4. Using Browser-based mail client, none of them have duplicated stuff anywhere that I can find. What documentation should I provide? Thanks.