Hi Catherine
Thanks for reaching out to Lucid support. Liberation Sans and Liberation Serif both support Greek lettering. Since the unicode is producing a symbol (ö) even though it isn't the expected one it seems to be related to the keyboard shortcut rather than to the font itself. I have let our development team know about this issue.
As a workaround so that you are able to continue your work in the meantime there are a couple of other ways that you can add a delta symbol into your text in Lucidchart:
- Copying and pasting the Greek letter from another resource into Lucidchart.
- Using the "Equations" shape library which supports mathematical operators Greek letters and other symbols.
Please feel free to let me know if you have any further questions!