Hello, Alwin.
 
     I believe there is a LabVIEW function that will do precisely what (I think) you want to do.  Am I correct that your intent is to replace the first row of a 2D Array, and you get strange behavior if you do a Delete followed by an Insert?  What happens if instead of doing two array operations, you just do a "Replace Array Subset"?
 
     I'd do a demo from your code, but I also cannot read LabVIEW 2023.  Try Replace (without the Delete) and see if that fixes the problem (it might also be faster, as a bonus).
 
Bob Schor