Subject: password is changed when connecting via script

I have a client to connect a sftp server. the password is complex. in the password there are some special character / ,+
with GUI, I could login in. but with the script. each it report access denied. I find the character / + is missing in the log file.

Here is the command line:
winscp.com /script=test.txt

Here is the script:
open sftp://user:pass@site/ -timeout=60
option transfer binary
close
exit

Please read
https://winscp.net/eng/docs/session_url#special