Users are allowed to set connection type (straight line, curved, etc.) default for their account.
Currently, users who prefer a type (I prefer curved) spend a lot of time changing connectors to their default type. I love this product, and I wish this was changed.
See this thread: https://community.miro.com/ask-the-community-45/how-to-set-default-line-type-as-curved-13552?postid=58645#post58645