.tip

PgBouncer in transaction mode hands a connection back after every transaction, so anything that lives on the session is gone: SET without LOCAL, advisory locks held across transactions, LISTEN, named prepared statements on older versions.

SET LOCAL statement_timeout = '2s';  -- survives pooling
SET statement_timeout = '2s';        -- leaks to the next client

Every session-level feature in your code is a bug in transaction mode. Grep for SET without LOCAL before you switch.