Hello,
I have checked this functionality on the newest FW - it was working without issues for me.Try to update your FW to the latest version.
If you will still be a facing any problems, please send a troubleshoot file of your router.
1) You can download it from your router's WebUI (System->Administration->Troubleshoot)
2) Send the file to me in a private message
Best Regards,
Lukas