There's no "Upload successful, but an error occurred while setting permissions/timestamp" error in the log.
Though there's another error, "The message ... is not extractable!", which is specific to your proprietary server and has probably similar root cause.
The log shows that timestamp preserving is on. Note that the log is from scripting running from some automation service. So your GUI configuration from user session has likely no effect on it.
See https://winscp.net/eng/docs/message_preserve_time_perm#scripting
Though there's another error, "The message ... is not extractable!", which is specific to your proprietary server and has probably similar root cause.
The log shows that timestamp preserving is on. Note that the log is from scripting running from some automation service. So your GUI configuration from user session has likely no effect on it.
See https://winscp.net/eng/docs/message_preserve_time_perm#scripting