For those of you trying to figure this out, the device connects to the phone's hotspot fine, correct? And then the device cannot reach the Internet through the phone?
Does the phone still have Internet at that point?
If you connect the computer to the phone's hotpsot, then examine the computer's network settings (command prompt --> "ipconfig"), what are the IP address, subnet mask, and default gateway assigned to the computer's wireless adapter? Can you ping the computer's address from the phone using a network toolkit app downloaded from Play store? Can you ping the phone's address (should be the gateway as seen in the computer's wireless adapter config while connected to the phone's hotspot) from the computer?
If you CAN ping the phone's address, can you also ping, say,
www.google.com? IF NOT, what if you ping the ip address directly, 172.217.1.238? Or another ip address, 8.8.8.8?