production deployment problem when selecting selecting dynamic search field

Hi,

http://www.safairmontgt.com.au/form_gt_master_1/

The above app works in dev on my local dev server. I deploy this to my Cpanel and i have issue when selecting a dynamic search.
Select add fields, pic 1, then select any field and i get what u see in pic2
my cpanle is php v7.3

pic1.PNG

pic2.PNG

to also add my dev php version is 7.2

Can anyone help…r there any log files i can look at