I can't see inital value field in data properties for local variables in Stateflow. What is wrong ? Do I have to change some settings for the model ?

I am developing a model in stateflow and I need to initialize some local variables. Due to the requirements of the code, initializing them at the beginning of the chart won't work. They also need to be written to, so I cannot assign them as parameters or constants. As local variables, I cannot see the Initial value field in the data properties. Is it due to some wrong settings of my Model ?