Installed:
  python3-configshell-1:1.1.30-6.el10.noarch            python3-kmod-0.9.2-4.el10.x86_64                        
  python3-pyparsing-3.1.1-4.el10.noarch                 python3-pyudev-0.24.1-7.el10.noarch                     
  python3-rtslib-2.1.76-7.el10.noarch                   python3-typing-extensions-4.9.0-4.el10.noarch           
  python3-urwid-2.5.3-2.el10.x86_64                     python3-wcwidth-0.2.6-3.el10.noarch                     
  target-restore-2.1.76-7.el10.noarch                   targetcli-2.1.58-1.el10.noarch   

/> iscsi/ create 
Created target iqn.2003-01.org.linux-iscsi.storageqe-72.x8664:sn.a6cc5a34e4cd.
Created TPG 1.
Global pref auto_add_default_portal=true
Created default portal listening on all IPs (0.0.0.0), port 3260. 
/> saveconfig savefile='/root/save1.json'
Configuration saved to /etc/target/saveconfig.json

/> saveconfig savefile='/root/save1.json'
Last 10 configs saved in /etc/target/backup/.
Configuration saved to /etc/target/saveconfig.json <- expected /root/save1.json here

 /> exit
Global pref auto_save_on_exit=true
Configuration saved to /etc/target/saveconfig.json

# pwd
/root
# ls | grep save
[Nothing], expect save1.json is shown


Run in batch mode, it works.
# targetcli  saveconfig savefile='/root/save2.json'
Configuration saved to /root/save2.json
# targetcli  saveconfig savefile='/root/save2.json'
Configuration saved to /root/save2.json
[root@storageqe-72 ~]# ls | grep save
save2.json