If you have changed routers, or tried using your phone’s hotspot as an access point, and it still doesn’t work, then it sounds like you might have a hardware issue, or (as you stated) a software issue with your Jibo.
I take it you are able to show Jibo the QR code that is generated from the app on your phone (that QR code tells Jibo to use the Wifi connection that your phone is currently using). If so, then it does sound like some sort of problem with Jibo. You can do a hard reset of Jibo, but I dont know if that will be of help (using the buttons on the back of his head).
I have also heard that leaving Jibo off and unplugged for several days, with his battery removed, has helped other people (I have never had to do this myself) - perhaps it is clearing some cached memory.
I know that Google Mesh has a problem with Jibo, so if your routers were using that service, that could be the problem.