I tried turned on automatic count of folder size but still I can not see the folder size in the properties dialog . This folder is accessed using ftp through wifi network
The Properties dialog for FTP folders won't show sizes, as they can take a long time to calculate on an FTP connection.
But you can show them in the file display itself, via Edit > Calculate Folder Sizes (Ctrl+K). If one or more folders are selected, it'll calculate the sizes of them only. If nothing is selected, it'll calculate the sizes of all folders below the current directory.
Thanks I tried ctrl+k and I get a folder size of 5GB in one second , but why size in properties dialog will be slower ?
Listing large/nested directories over the internet is usually quite slow, and something we only do on FTP sites when explicitly requested. The Properties dialog shows a lot of other information, so there's no way to know it's being opened for the folder size.