I'm using Notepad++ (v7.9) and am working with some special Unicode characters used in IPA (International Phonetic Alphabet) like ð (eth) or ŋ (eng). These characters are defined in Unicode. I've been able to successfully copy and paste them into Notepad++, and that part works fine. I can also save to a text file (with UTF-8 encoding) successfully.
However, if I reopen the file in Notepad++, they do not render correctly. "ð" becomes "รฐ", and "ŋ" becomes "ล‹" (it looks like a character similar to "a", followed by "PLD" in the highlighting similar to what I'd see in a null character).
If I open the same file in Notepad (the Windows program, not Notepad++), the characters appear fine, so I figure it must be an issue with either reading the file or rendering the text. It's also possible it could be a font issue, but I'm using the default font.
How can I get Notepad++ to display these characters correctly?