The tether app will not let me unblock a client. I am tryin to set up my kids Amazon Fire HD 10 tablet and I am getting "internet, no connection".  Looking at the tether app i see the device is being blocked and whne I slide the client to unblock it, I get a message 'cannot unblock client. please try again later". Well I have been trying for Dayyyyyys. What gives?!  Any advice from some experts out there?