Check the following before taking any further actions:
If your credentials were entered correctly and the network is indeed online, you might have issues connecting due to network settings such as firewall, vpn or proxy.
You can also try to manually configure your Sensibo device to connect to your WiFi network. Follow this guide to do so.
Sensibo devices connect to home.sensibo.com on ports 443 and 80. Please make sure these ports do no have any restrictions on them that could prevent Sensibo devices from connecting successfully to the internet through them.
Sensibo needs DNS access. The DNS server address must be given via DHCP of your router.
Your internet providers could have a built-in firewall or proxy. Please check with your ISP.