Quoting from https://neo4j.com/docs/python-manual/current/session-api/#_transaction_timeout

Note: Using with Neo4j 4.1 and earlier it is possible for the driver to override any value set with dbms.transaction.timeout. In 4.2 and later, dbms.transaction.timeout also acts as a maximum which the driver cannot override. For example, with a server setting of dbms.transaction.timeout=10s the driver can specify a shorter timeout (e.g. 5 seconds) but not a value greater than 10 seconds. If a greater value is supplied the transaction will still timeout after 10 seconds.

so I added a note in the related docstring accordingly.