Display top layer objects over default layer objects

Hello, I’m using lvgl 7-6-1 and I have the following situation:

lv_obj_t * obj1 = lv_obj_create(lv_layer_top(), NULL);
lv_obj_t * obj2 = lv_obj_create(lv_scr_act(), NULL);

I’d expect obj1 overlaps obj2, but it’s not: obj2 covers obj1.

Did I get wrong how drawing layers should work?
Should I do anything particular in the driver implementation or in lv_conf.h?

Thank you in advance

What’s wrong with this thread?
Uhm … I see it’s grayed and nobody replies.