Restrict LV_STATE_FOCUSED to within a specific object

Description

I have two objects on my screen, a control box and a list of sub-objects.
When I touch a sub-object in the list, it gets focus and has the LV_STATE_FOCUSED state set.
The problem is that if I touch anything in the control box, the sub-object loses focus.

How can I prevent interaction between the list and the control box?

    lv_obj_t * ctrl_box = create_ctrl_box(parent);
    lv_obj_t * list = object_list_create(parent);

What MCU/Processor/Board and compiler are you using?

Raspberry Pi 3B+ gcc 12.2

What LVGL version are you using?

9.0