Possibly there is a rogue setting on your iPhone. Try and delete the iPhone App then restart the phone and reinstall it.
To me it looks like your iPhone isn't listed in the list of connected devices on your router connection table. We can only see the B2
Which iOS version is your iPhone using? Possibly the Brennan App won't work well on very old versions of iOS for iPhone. In any case if you can update the iOS and reboot your phone as well. Then reinstall the App
Which Wi-fi Network is the iPhone connecting to? 2.4 Ghz or 5Ghz?
1. As John says, what's the IP address of the iPhone on your wireless network?
2. Make sure that in - iPhone ->settings->Wi-Fi is on and then go into the settings for your network and double check these
Wi-Fi -> ON
Network Name - should be displayed
3. Auto Join - should be ON
4. Private Address - ON
5. Low data Mode - OFF
6. Configure IP - Automatic
7. IP Address - should read the same value as the setting for your iPhone shows your router as in step 1
8. DNS
configure DNS -> Automatic
9. HTTP Proxy
Configure Proxy -> OFF