oops! 503 Service Unavailable Centos

[svenms]

Dears,

I am having a 503 Error when saving the Menus on Wordpress "https://mysite/wp-admin/nav-menus.php" but the changes are saved into the website.
When I check logs there is no other related error.

2021-04-28 23:48:52.618793 [INFO] [3404] Rewrite directive: <IfModule mod_php5.c> bypassed.
2021-04-28 23:48:52.618814 [INFO] [3404] Invalid rewrite directive: php_flag engine 0
2021-04-28 23:48:52.618817 [INFO] [3404] Rewrite directive: </IfModule> bypassed.
2021-04-28 23:48:52.618819 [INFO] [3404] Rewrite directive: <IfModule mod_php7.c> bypassed.
2021-04-28 23:48:52.618822 [INFO] [3404] Invalid rewrite directive: php_flag engine 0
2021-04-28 23:48:52.618824 [INFO] [3404] Rewrite directive: </IfModule> bypassed.
2021-04-28 23:48:52.618826 [INFO] [3404] Invalid rewrite directive: AddHandler cgi-script .php .phtml .php3 .pl .py .jsp .asp .htm .shtml .sh .cgi
2021-04-28 23:48:52.618829 [INFO] [3404] Invalid rewrite directive: Options -ExecCGI
2021-04-28 23:48:52.618840 [INFO] [3404] RewriteFile [/home/mysite/public_html/wp-content/uploads/.htaccess] parsed, return 0.
2021-04-28 23:49:09.134813 [NOTICE] [3404] [141.101.103.65:30752#chilevapo.cl] oops! 503 Service Unavailable
2021-04-28 23:49:09.134833 [INFO] [3404] [141.101.103.65:30752] Content len: 217604, Request line:
POST /wp-admin/nav-menus.php HTTP/1.1

I disabled CFS and Modsecurity.
Changed Php versión
Increased php memory to 512 MB
Max_input_time 120

What would you recommend me to check additionly?
I haven't done or installed other things after Cyberpanel.

Cybepanel 2.0.3

Thank you very much!