Steps to reproduce:
1.Open any pdf file
2.Add a sticky note
3.Enter the text 𝒟b.
4.Close the sticky note.
5.Point with mouth on the sticky note.
6.Observe that the text is displayed as ▯b.

Notes:
1. If you enter just 𝒟 or 𝒟 followed by Arabic Letter Mark it will be displayed correctly.
2. Enter the Unicode of those characters and Alt-X to enter these characters.
3. Same bug occurs with text of Highlighted text.

Environment:
Windows 10 Home 22H2 (19045.3324), Adobe Reader 23.003.20284.0
2.