SET LOCAL doesn't become undefined after transaction is commited

We are using dynamic settings via SET LOCAL for row level security.

I would like to clarify that I'm seeing the correct behaviour

I create a new session to the database, I run the following query:

SELECT current_setting("session.my_tenant_id");

I will get the following error:

pq: unrecognized configuration parameter \"session.my_tenant_id\"

However, once I run the following transaction

BEGIN READ WRITE

SET LOCAL session.my_tenant_id="f00";

SELECT * FROM someTable;

COMMIT;

Then

SELECT current_setting("session.my_tenant_id");

will return an empty string "". Basically "session.my_tenant_id" becomes defined.

Is this supposed to work like this or could this be a bug?

Is it possible to entirely undefine "session.my_tenant_id" after the transaction was committed? Basically I would like to return to the initial state of the PSQL connection.

Thanks in advance.