Could you please double confirm the following information?
1. Make the computer and device in the same Wi-Fi network.
2. Disable the Windows firewall.
3. Right click 'My PC' in your computer, then select 'Manage'->'Service and Applications'->'Services', then find out the Nero. BackItUp service with name "Nero BackItUp Background service xxx", select it and right click with 'Restart' by mouse.
Thanks for your supporting of Nero!
Nero Support Team