--sftp-set-env issue

Executing this I have an issue. All the SSH connections seems okay, with the env var set except the first one:

rclone sync "$HOME/MEGA/HOME/_documents" "pi3:/mnt/raid-1/_documents" --exclude ".DS_Store" --exclude "._.DS_Store" --sftp-set-env "SSH_REASON=rclone-backup-documents" --progress --interactive