Below is markup for example of issue. Notice when the "\n" is removed from the one note. You can see each link properly, otherwise this does not look like rendering correctly.
a -> b: some text
note over a, b: This flows starts from [[www.yahoo.com POST/session/start]] \nor [[www.google.com POST /session/csrStart]]
note over a, b: This flows starts from [[www.yahoo.com POST/session/start]] or [[www.google.com POST /session/csrStart]]