Hi,
You need to be using current Hueman Theme and Hueman Addons plugin.
Go to Appearance -> Customize -> “site wide options tab” -> Header design -> Header menus
Find the setting -> Select the menu(s) to use for mobile devices
Select -> Topbar and header menus, logo centered
This is the only option that has search icon visible in mobile, the search field is within mobile menu for the other two options.
The option -> Mobile devices : display a search field
Refers to a search field which means a search input. Does not refer to search icon. All three options in -> Select the menu(s) to use for mobile devices contains a search field. There is no bug here.
Here’s a related documentation which could provide more details.
https://docs.presscustomizr.com/article/282-managing-the-header-menus-in-the-hueman-theme
Thank you