[12:55:18] CWD 'TMP'
[12:55:18] 250 "TMP." is the working directory name prefix.
[12:55:18] 257 "'TMP.'" is working directory.
[12:55:18] 200 OK
Note that the command seems to have been converted to CWD 'TMP'. The z/OS ftp server will interpret this as a request for an MVS dataset TMP. If the command origianlly sent in the command line where passed to the z/OS FTP as entered the fpt server would handle the request properly. Smartftp has been able to handle this in the past but each new version seems to re-introduce the problem.
I also note that once I have entered the command, that Smartftp appears to re-try it repeatedly as observed by the fact that the log sequence above is repeated about every 20 secs.