php - SSH to Fortigate firewall failing using phpseclib

Question

I am trying to execute the below command on fortigate using my php script using library phpseclib.

 config global

 exec batch start

 conf vdom
 edit [PORT_VDOM]

 conf firewall addrgrp  
 edit "[GROUP_NAME]"  
 set member "[MEMBERS]"
 end  
 exec batch end

I am executing the above command using ssh in a php script. It does edit the group successfully if I add few members. If I add more members, it is not editing the group.

however, If I execute the set member command with more members directly on the cli, it is editing successfully. Issue is occurring just when the command runs from the script only when the set member command has about 40 members.