css – Remove a style from style-m

this style is causing an issue with my mobile menu.

  .navigation .submenu:not(:first-child).expanded {
    display: block !Important;
  }

I have tried to overwrite it but it still appears as a duplicate. Is it possible to remove this completely from my theme.

I am trying to replace the rule with

  .navigation .submenu:not(:first-child).expanded {
    display: none;
  }

I cant use none !important because that then breaks something else. So thats why i need to remove it completly