cart.php?a=checkout delay

[lyra2018]

Hello,

I am having problems once the order is completed by the client, the page hangs 1min(it is loading but any loader is being shown) before proceeding the next step (cart.php?a=complete)

 

 

WHCMS version 7.5.1

PHP version 7.2:

Functions disabled:

system,system_exec,symlink,shell,shell_exec,exec,passthru,proc_close,proc_open,ini_alter,dl,show_source,proc_get_status,proc_nice,proc_terminate,highlight_file,define_syslog_variables,posix_uname,posix_getpwuid,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,ini_restore,inject_code,syslog,openlog,define_syslog_variables,apache_setenv,eval,phpAds_XmlRpc,phpAds_remoteInfo,phpAds_xmlrpcEncode,phpAds_xmlrpcDecode,xmlrpc_entity_decode

Can you help me please?

Regards