Column Formula not working for some people in group, why?

Hello!

My company has a PowerApps connected into a SharePoint list. 

One of the columns of the list has a formula:" ="NS-"&TEXT(Created,"yy")&"-"&[NSP number] "

This was created so that the column reads: NS-YY-ID, this works when I add a new entry, but not when other people do. Is there any specific permission I should work on? or is this not working correctly. 

Please, any idea why this is happening? Thank you in advanced!