Let me please continue this topic a little. I spent a whole bunch of time to find the answer.
As to version LVGL 7.11.0 (and 7.9.1 and maybe earlier) next link is the only way I could find the solution:
set state LV_STATE_DISABLED by lv_obj_add_state () and clear it by lv_obj_clear_state ()
Hope this can help to someone.