Thanks to the suport team, I was able to solve the problem.
The createMock object must be created as handle-class object by using ?handle as second input argument. The get value definition should be created as well with the Invoke method.
The working solution looks like this:
classdef TestMotorization < matlab.mock.TestCase
    properties
        myMotor
    end
    methods (TestClassSetup)
        function creatMocks(testCase)
            import matlab.mock.actions.Invoke
            import matlab.mock.actions.StoreValue
            import matlab.mock.actions.AssignOutputs;
            [motorMock, motorBehaviour] = createMock(testCase, ?handle, ...
                'AddedMethods',{'moveToPosition','getCurrentPosition'},'AddedProperties',{'currentAngle'});
            % Setup behaviour
            when(set(motorBehaviour.currentAngle),StoreValue)
            when(withAnyInputs(motorBehaviour.moveToPosition),Invoke(@setValue))
            when(withAnyInputs(motorBehaviour.getCurrentPosition),Invoke(@getValue))
            % Keep as TestCase property
            testCase.myMotor = motorMock;
            function setValue(obj, newAngle)
                positioningOffset = 0.01;
                obj.currentAngle = newAngle + positioningOffset;
            end
            function angle = getValue(obj)
                angle = obj.currentAngle;
            end
        end
    end
    methods (Test)
        function testMoveMotorizationSuccess(testCase)
            testCase.myMotor.moveToPosition(2.1);
            currentPosition = testCase.myMotor.getCurrentPosition();
            testCase.verifyEqual(currentPosition, 2.11);
        end
    end
end
