Edit view glitch

When I break a line with the typeface I am making, some mysterious characters are inserted (I don’t know what writing system it is) and the app will crash when I try to edit it by double-clicking. It’s as if it’s breaking at a wrong point of the hexadecimal string? I am using a custom glyphs data and the Unicode range is 11580—115DD for your information.

Can you send me the file with that tab open?

I quit the app with this state and reopened it. The string is not preserved but many characters are duplicated instead, so I cannot send you the file as it is.

The send the text in a text file.