I had this same issue. My phone would find the wifi hub and attempt to connect it. After selecting the WiFi network for it to join, it would continue but then time out and say that the wifi hub could not connect to the internet.
I tried all the usual resetting etc a million times. Eventually, when setting up the WiFi, I de-selected the ‘DHCP’ option for the networking and configured a static IP address etc. This seemed to resolve the issue for me.
I am not 100% confident this resolved it (there were still some odd things going on), but at least it is another option for users seeing this thread to try.