How to insert an element in the center of a Vuex array?

Question

JavaScript

Hello.
I have a vue table using vuex.
It is necessary to add a column to the table (in the middle, for example), but so that the table would completely re-render the indexes, because I use indexes.
in mutation I call

state.cols.splice(toIndex,0,payload.newColumnContent)

the column is added, but the indexes are shifted and my table breaks.
it is necessary to re-render the table when adding. or to force to recalculate indexes. How to do it?