Issue with Upload and systemd PrivteTmp set to true.

I am using.
Raspberry Pi 4, latest Buster version.
Tomcat9, installed with apt-get

The install of tomcat9 uses the systemd program to execute the tomcat server.
The systemd configuration file for tomcat has the PrivateTmp set to true, this causes a temp directory to be created with a name like
/tmp/systemd-private-bd1d4a960b8448e0aa7b5ad932a7fc5a-tomcat9.service-lQLUkR/tmp .
This temp directory will be removed if the tomcat server is shutdown, restarted or the system is rebooted.
The Upload widget will allow me to upload a file to the above directory but I can not move/copy the file to another directory to save it.

So I tried setting the PrivateTmp to false and it no longer creates a temp directory but I can not write to the /tmp directory from the Upload methods, even when the /tmp directory has read/write for all.

What am I doing wrong?
How are others getting around this issue?

Thanks for any help.