You can try the follwoing solutions when you connect your devices to rockspace extender's network but there is no Internet. After each step, check if the issue is fixed with your phone or computer.
Troubleshoot no Internet when connected to extender's networkStep 1. Check Internet connection
Connect an end device (your smartphone or computer) to the main router directly to check its internet connectivity. If there is no Internet, contact your Internet Service Provider for help.Step 2. Check the extender’s location
If your extender is beyond the range of your main router, no signal can be received, thus no Internet connectivity. You can visit where to place Wi-Fi range extender to get more tips.Step 3. Reboot the range extender
Disconnect and reconnect the range extender from the power source. Wait until the Power LED on the range extender is ready.Step 4. MAC Filtering or Access Control
Check whether the MAC filtering or Access Control is enabled on your wireless router. If it is, you can disable the MAC filtering or Access Control, or add the extender’s Mac Address to the whitelist.Step 5. Reset the range extender