A major update to the Visual Constructor is released on May 11th.
You could not Edit API operations after the initial Save, only duplicate and edit a new one.
This was related to difficulty tracing where you use existing internal or external API operations, so if you changed it, you could have missed a place in your application to double-check if the logic of the edited Operation still fits.
Since a search tool was released in Q1 of 2021, we can now ensure you will find every place in App, where you use the edited operation.
Now -> the platform allows editing and saving on any existing Operation.
As usual - Looking forward to your questions and comments in the Support channels.