Using QFileInfo to read the permission of the file in the remote host mounted by ftp, the result is abnormal

Mount to the remote host via ftp: "ftp://10.5.10.1", and log in. One of the file permissions is readable, non-writable, and non-executable. It is normal to use the command line to view the permissions in the terminal.
Write a program, call isExecutable(), isReadable(), isWritable() in QFileInfo, read the file permissions, and the returned results are all true.
Through further inspection, the result returned by calling permission() is also abnormal.
Copy the remote file to the local, call isExecutable(), isReadable(), isWritable() to read the file permission, and the returned result is correct.
Details can be found in the attachment.