As discussed previously on now-archived page https://support.mozilla.org/en-US/questions/1421215, there seems to be no way to un-ignore a sub-thread that has been ignored. I've gone to the parent thread and un-checked the "Ignore Subthread" option (and cycled this several times) and no matter what I do, the sub-thread remains invisible. When I view the entire conversation using "Open Message In Conversation" from the parent email, I see the sub-thread, and it has the red "ignored" marker. When I hover over the marker, I get the message "This Subthread is ignored". Left-clicking the marker does nothing. Right-clicking it produces the same dialog box that I get by right-clicking anywhere on the ignored thread, offering no option to un-ignore the thread. I tried copying the ignored thread to my inbox, and this produced a copy of the ignored thread that is also ignored and cannot be un-ignored. I am guessing that the problem has to do with the fact that THE IGNORED THREAD IS NOT A DIRECT CHILD OF THE PARENT. Please see the attached images. SO THIS IS A BUG. It is not reasonable that the child thread remains ignored when I un-check the "Ignore Subthread" option on the parent email. It is also not reasonable that the "Conversation" view that actually displays the ignored thread and tells you that it is ignored offers no way to un-ignore the thread. I am running Thunderbird version 128.5.1esr (32-bit) on Windows 10, and Thunderbird says that it is up to date.