Exemption of Family leave insurance employee tax for washington state

Employee from WA state should be exempt from withholding FLI employee tax. We had created one custom tax element and using FF, passing negative value so it set the current amount of FLI to zero. Example Seeded FLI for WA state is tax is 10 and Custom tax element would be negative 10. Balance definition was updated to pass custom tax element input value tax calculated to seeded Family Leave insurance employee tax balance.

On SOE, current of FLI shows zero however year to date still shows up. Any idea what could be done differently?