If you open composition mode, then select two or more words and press SHIFT+F4 (add note shortcut) you'll end up with two notes instead. The first attached to all the selected words except the last one, the second one attached to the last selected word only.
eg. selecting the following text
- the quick brown fox
and SHIFT+F4, ends up with
- note 1 attached to "the quick brown" - note 2 attached to "fox"
This only happens ONCE per composition mode. To retrigger this bug, you have to close such mode and open it again.