Does your /usr/local/directadmin/data/admin/services.status file have any services defined?
[root@server1 ~]# cat /usr/local/directadmin/data/admin/services.status
clamd=ON
da-popb4smtp=ON
directadmin=ON
dovecot=ON
exim=ON
freshclam=ON
httpd=ON
lfd=ON
mysqld=ON
named=ON
php-fpm56=ON
php-fpm73=ON
php-fpm74=ON
php-fpm80=ON
pure-ftpd=ON
rspamd=ON
sshd=ON
Please attach JSON output from URL/CMD_SHOW_SERVICES?json=yes&bytes=yes&ipp=50
and also check your browser's console for errors.
{
"actions":
{
},
"memory":
{
},
"pids":
{
},
"status":
{
}
}