How to remove flag?

So i added flags but i don’t want to use them anymore.
But i can’t remove them!

The problem is that in chrome i can hide them in the backend but in firefox i get an url in the dropdown select and i don’t want that.

so please how to remove the flags? Don’t tell me to go in the backend and put show flags to no because it does not work!

https://wordpress.org/plugins/woocommerce-currency-switcher/