This still happens on Thunderbird 91, so have reported it upstream: https://bugzilla.mozilla.org/show_bug.cgi?id=1739405
** Bug watch added: Mozilla Bugzilla #1739405 https://bugzilla.mozilla.org/show_bug.cgi?id=1739405 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1916586 Title: Adding word to dictionary doesn't update subject To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1916586/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs