I was able to reproduce this by following the instructions. Note that you must not have EditEngine forms defined, because maniphest.default-priority is not used if you're creating a task with a customized form (instead, the form default value is used).
This "fixes" it but a better fix is likely a little more involved:
diff --git a/src/applications/maniphest/constants/ManiphestTaskPriority.php b/src/applications/maniphest/constants/ManiphestTaskPriority.php index d559299af..9b3c32499 100644 --- a/src/applications/maniphest/constants/ManiphestTaskPriority.php +++ b/src/applications/maniphest/constants/ManiphestTaskPriority.php @@ -32,7 +32,10 @@ final class ManiphestTaskPriority extends ManiphestConstants { } foreach ($words as $word_key => $word) { - $words[$word_key] = phutil_utf8_strtolower($word); + $lower_word = phutil_utf8_strtolower($word); + if ($word != $lower_word) { + $words[] = $lower_word; + } } $words = array_unique($words);
Another "fix" is to perhaps to remove maniphest.default-priority since EditEngine forms can set defaults for any field, including priority.