problem changing jsonb attribute to null value

Hello:

I have a problem with a record in a jsonb type table, I'm trying to
change the value of an attribute to null but it leaves me all the
content in null and not just the value, I show you an example first of
how to define the null attribute:

prueba=# select jsonb_build_object('v', null);
 jsonb_build_object 
--------------------
 {"v": null}
(1 fila)

this jsonb record is correct, then when trying to change the value with
jsonb_set with some value of type jsonb, it does it correctly:

prueba=# select jsonb_set('{"v" : 0}'::jsonb, '{"v"}', to_jsonb(1));
 jsonb_set 
-----------
 {"v": 1}
(1 fila)

but if i try to put the null value in "v" attribute, apparently is not
allowed:

prueba=# select jsonb_set('{"v" : 0}'::jsonb, '{"v"}', to_jsonb(null));
ERROR:  no se pudo determinar el tipo polimórfico porque el tipo de
entrada es «unknown»

defining null value as a text type:

prueba=# select jsonb_set('{"v" : 0}'::jsonb, '{"v"}',
to_jsonb(null::text));
 jsonb_set 
-----------
 
(1 fila)

it leaves the record in null, when I hope it leaves it with the null
value in attribute "v": {"v": null}

thank you for your help!!!!

Regards!!!!