Your exampleClass is a value class. However, the behavior you describe is more like that of a handle class. See the examples below. (To run the code I need to attach the classdef-files rather than including them in this text.)
%% value class
v = exampleClass(1);
v1 = v
v2 = v
v1.exampleProp = 5
v
v2
%% handle class
h = exampleClass_handle(1);
h1 = h
h2 = h
h1.exampleProp = 5
h
h2
