Overwrite values from Map List 1 to Map List 2 better use Loop instead Loop Variable

I’m trying to overwrite some values in one Map List with corresponding values from another one. I tried using “Loop Variable” to solve it but, It does not work. Then I tried using a "loop" instead, then boom it worked. So, I suggest you use Loop for the same condition as me. I would recommend to processes the values based on their index.

My Scenario can be seen below.

Figure 1: Loop Variable scenario does not work

Figure 2: Loop scenario does work