❔ OnpropertyChanged WPF

Hi everyone, i have

_stepStore_PropertyChanged

_stepStore_PropertyChanged

which is subscribe to

_stepStore.PropertyChanged

_stepStore.PropertyChanged

and i do not understand why my method is trigger twice ?
if i put a breakpoint on the on both side one on the propertychanged in

_stepStore

_stepStore

and the other one in the method it not match like there is only one trigger inside

_stepstore

_stepstore

against 2 for the method.