Elasticsearch not starting on redhat7 bootup but does manually post reboot

Hi,

I'm running Red Hat Enterprise Linux Server release 7.2, and elasticsearch-7.1.1-1. I used the standard RPM installation and enabled elastic to start on bootup. During the bootup I see..

Sep 11 17:07:55 xxxxx systemd[1]: [/usr/lib/systemd/system/elasticsearch.service:62] Unknown lvalue 'LimitMEMLOCK' in section 'Install'
Sep 11 17:08:19 xxxxx systemd[1]: Started Elasticsearch.
Sep 11 17:08:19 xxxxx elasticsearch[20719]: Exception in thread "main" java.nio.file.NoSuchFileException: /tmp/elasticsearch-4853629912132676055
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/sun.nio.fs.UnixFileSystemProvider.createDirectory(UnixFileSystemProvider.java:389)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/java.nio.file.Files.createDirectory(Files.java:692)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/java.nio.file.TempFileHelper.create(TempFileHelper.java:135)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/java.nio.file.TempFileHelper.createTempDirectory(TempFileHelper.java:172)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at java.base/java.nio.file.Files.createTempDirectory(Files.java:1009)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at org.elasticsearch.tools.launchers.Launchers.createTempDirectory(Launchers.java:66)
Sep 11 17:08:19 xxxxx elasticsearch[20719]: at org.elasticsearch.tools.launchers.TempDirectory.main(TempDirectory.java:54)
Sep 11 17:08:20 xxxxx systemd[1]: elasticsearch.service: main process exited, code=exited, status=1/FAILURE
Sep 11 17:08:20 xxxxx systemd[1]: Unit elasticsearch.service entered failed state.
Seyp 11 17:08:20 xxxxx systemd[1]: elasticsearch.service failed.

If i start it using "systemctl start elasticsearch" post reboot it works fine and stays running.

I can see that systemd-tmpfiles-setup does seem to start prior to elasticsearch starting.

Any tips / advice on resolving this greatly appreciated. This is my first post so apologies if I've not provided all the required information.