Observation on Airtable and a way out

First Observation

In my observation, i have a list of ten items which are stored in an empty list. My aim is to set the value of the list to NILL, when doing so i discovered that not all the values are set to NILL. For the first try index 8 will not be set to NILL, the second try index 2 will not be set to NILL, maybe the third try or some other try all the values will be set to NILL- I used for each number in list.

Second Observation

This part of the observation gave me a though time, i spent time figuring out what was wrong and finally changed my approach thou i knew the simple way to do it but just trying another approach.

I want to fetch 10 items, instead of using “Get column” the simple way of fetching items, i used Get cell inside a loop- Get cell is used to get a single value, but my assumption was that since am using a loop i should be able to get all the items in a single stretch.
i discovered that the items gotten are not listed accordingly, then i compared it with the value using Got column and i saw that the list are not corresponding. It took me time to figure-out what was happening

From the observation, can anyone devise a means of preventing the first observation from occurring, this is just 10 list not to talk of 50 or more lists.