You need to be in 'seller hub'.
Choose your active listings and 'bulk edit' and all of your items.
Right at the top, the first choice from the dropdown edit menu is 'auto-relist.
You need to choose 'don't allow'.

"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)