Database Backup Only Works In Php Version 7.4

Ever since last November we have been unable to do Sytist database backups from Sytist.  We updated the PhP version in November from 7.4 to 8.1 and lost that functionality.  I was able to do backups from the host cpanel just fine though.  I reverted back to 7.4 today as a test and I was able to backup once again via Sytist.

Is it okay to use an older version of Php (7.4)?

Works for me on 2 different servers running PHP 8. Your PHP 8 configuration may have the system() function disable.

Using PHP 7.4 is fine.

Backup via Sytist also not working for me since upgrading to PHP 8.1.

Optimise database function seems to work ok but database backup just through up a blank screen 

Sytist version 5.2.4

I can't see the system () function in any of the php options on the server, and I have full root access to rebuild and intsall php versions and options and the apache RPM. Where should I look?