restrict data from select with Row-Level Security when updating
By default, row level security does not apply to the owner of the table.

If you want that, you got to

ALTER TABLE tbl2 FORCE ROW LEVEL SECURITY;


There are some other settings that may cause RLS not to be used:


If the configuration parameter row_security is off.
If the user is a superuser.
If the user was created with BYPASSRLS.