If you drag pin to Event you will automatically create an input with wrongs settings.
Engine forget to set “Const” in property
There is Note about it.
But if you recreate input manually the “const” will be setted to true. And note is now gone.
Confirmed this is still an issue in 5.7
The problem is the Const option doesn’t always get set, if this shows up you can change the type to something simple … say a single int, you will notice the Pass by Ref and Const values change … pass by ref becomes editable and const unchecks and is read only
Changing it back to an array and whatever type you were after should cause it to set the proper defaults