maksymyushytsyn

I rolled back to the previous version.

Me too. I crashed many posts ??

You need to detect and block IPs that are accessing the site at a high frequency. Usually, a log file on the server is used for this. Many hosts can provide protection against parsing, check with your provider.

This is a folder and file permissions issue (depends on server settings). The best way to edit files is to use FTP clients (FileZilla, Notepad++).
Try adding the following code to your root wp-config.php file (AT THE END OF THE FILE!):

if(is_admin()) {
	add_filter('filesystem_method', create_function('$a', 'return "direct";' ));
	define( 'FS_CHMOD_DIR', 0751 );
}

Problems with all <title>

Custom posts. Created using Advanced Custom Fields 5.7.7
Until the last update worked correctly