Using lv_arc with encoder doesn't work

Description

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

ESP32+TFT_espi+Arduino on PlatformIO

What LVGL version are you using?

8.3.4

What do you want to achieve?

I tried to add an lv_arc to the demo_keypad_encoder example

What have you tried so far?

Adding to the group did not work for lv_arcs (I copied and adapted the code from the online manual). The arc is drawn, but it gets no focus. It’s more like “OK, I know now, that I selected the arc, now I can turn the know to change its value”

So:
arc → no focus visible, can change the value blindly

Code to reproduce

static void selectors_create(lv_obj_t * parent)
{
    lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
    lv_obj_set_flex_align(parent, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);

    lv_obj_t * obj;
    obj = lv_spinbox_create(parent);
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);

    obj = lv_label_create(parent);
    lv_label_set_text(obj, "Speed simulation");
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);

    obj = lv_switch_create(parent);
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
    
    obj = lv_label_create(parent);
    lv_label_set_text(obj, "Speed");
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);

    obj = lv_bar_create(parent);
    lv_obj_set_size(obj, 200, 20);
    lv_obj_center(obj);
    lv_bar_set_value(obj, 70, LV_ANIM_OFF);
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
    lv_group_add_obj(g, obj);

    obj = lv_label_create(parent);
    lv_label_set_text(obj, "Volume");
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);

    obj = lv_arc_create(parent);
    lv_arc_set_range(obj, 0, 64);
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
    lv_group_add_obj(g, obj);

    obj = lv_label_create(parent);
    lv_label_set_text(obj, "Start DOOM");
    obj = lv_switch_create(parent);
    lv_obj_add_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
}

I updated my question: Removed bar as I was completely wrong (using a slider now)