I have two consecutive slides titled "Jewish calendar" and "Muslim calendar". I added the Unicode character with the relevant religious symbol before and after either title.
Now as I type the title, the symbols are visible. But as soon as I click somewhere else, removing the focus from the title field, the Stars of David become invisible. The Crescent symbols do not; they are OK.
I thought it might be a problem with the font I use, so I switched the Stars-of-David to Times New Roman, then to Arial, hoping those are standard enough, but it didn't help.
