Doctrine Connection beginTransaction method also calls connect, but implicitly on the slave connection which overwrites master

Connection.php

<?php

class Connection
{
    public function beginTransaction()
    {
        $this->connect();

        // **** Note: transaction nesting level is NOW incremented, so connect method does not consider it ***
        ++$this->_transactionNestingLevel;

        $logger = $this->_config->getSQLLogger();

        if ($this->_transactionNestingLevel == 1) {
            if ($logger) {
                $logger->startQuery('"START TRANSACTION"');
            }
            $this->_conn->beginTransaction();
            if ($logger) {
                $logger->stopQuery();
            }
        } else if ($this->_nestTransactionsWithSavepoints) {
            if ($logger) {
                $logger->startQuery('"SAVEPOINT"');
            }
            $this->createSavepoint($this->_getNestedTransactionSavePointName());
            if ($logger) {
                $logger->stopQuery();
            }
        }
    }
}