php-fpm unable to connect to active socket

I changed from PHP 5.6.30 to PHP 7.2.9 and now I am unable to run scripts that access pgsql using socket 5432. The old PHP 5.6.30 works as expected. The configuration is apache using php-fpm to execute the PHP scripts. scripts that use PHP but do not connect to the database seem to work OK but haven't been fully tested yet. php-fpm is started using the systemd script included with the download. Formerly PHP 5.6.30 was started as an init.d script. Error message is: --------------- Warning: pg_connect(): Unable to connect to PostgreSQL server: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/tmp/.s.PGSQL.5432"? --------------- ls -a /tmp/.s.* /tmp/.s.PGSQL.5432 ss -a | grep 5432 u_str LISTEN 0 128 /tmp/.s.PGSQL.5432 29050 * 0 Restarting PHP 5.6.30 immediately reconnects to socket 5432 as always and all scripts calling the database work as expected. I have stopped and started both versions of PHP multiple times, and also pgsql, so it doesn't appear to be a lock on the socket from PHP 5.6.30 causing the problem. The configure parameters to make are (taken from php_info): './configure' '--prefix=/usr/php-7.2.9' '--with-apxs2=/usr/apache- 2.4.25/bin/apxs' '--enable-fpm' '--with-fpm-user=phpfpm' '--with-fpm- group=phpfpm' '--with-fpm-systemd' '--disable-short-tags' '--with- openssl=/usr/openssl-1.1.0i' '--with-zlib' '--with-pgsql=/usr/postgres-9.6.2' '- -with-pear' '--with-libxml-dir=/usr/lib64' Can anyone see anything that might be causing this? Or suggest some way to try and debug it? Thanks in advance. John