Per the documentation (https://lucidchart.zendesk.com/hc/en-us/articles/208029986), the following markup:
note over Bob, Alice: This is an example of a
with a line break. End note
Should result in: "Add a note shape with multiple-lined notes, displayed over Alice and Bob.", but it does not. It causes a syntax error:
Also, it appears that there is more markup syntax that is not documented from my experiments trying to make multi-line notes work. But the immediate problem is that the current documentation is incorrect for multi-line notes.