Please can you help with this:
root@na7kr:/usr/lib/php/20180731# /usr/bin/php /var/www/na7kr-us/data/cron_bridge.php
PHP Warning:  PHP Startup: Unable to load dynamic library 'lua.so' (tried: /usr/lib/php/20180731/lua.so (/usr/lib/php/20180731/lua.so: undefined symbol: ZEND_HASH_GET_APPLY_COUNT), /usr/lib/php/20180731/lua.so.so (/usr/lib/php/20180731/lua.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
PHP Warning:  Module 'MapScript' already loaded in Unknown on line 0

My guess is that you have a PHP lua extension compiled against a different version of PHP that you are running.

now get this:
PHP Warning:  Module 'MapScript' already loaded in Unknown on line 0
 

My guess would be your php.ini is somehow loading 2 different versions of PHPMapScript.MapTools.org.