So, I've been pretty busy with work and haven't had a chance to test ipconfig. I had thought my first post covered this, but maybe I forgot.
All internal network IPs can be pinged, and indeed network shared drives even work. The internal IP for the gateway can be pinged, but not the external IP address for the gateway. No internet web addresses or IP addresses can be pinged.
Well, the first post said it connected to the computer but the Internet didn't work, but in my experience with IT work that means different things to different people. I was just trying to be specific enough to put the nail in the correct coffin.
Definitely, if multiple devices connecting to your phone's hotspot are able to communicate between themselves over that network, then the WiFi part of the configuration is good on both ends.
Problem could still be bad default gateway. Even with the wrong address for gateway, the devices would still be able to communicate between themselves because they're all on the same network segment. So we still need to check that to be sure. If it proves to be the wrong address being used for gateway, it would be simple (though time-consuming) to reconfigure all the devices to manually assign this. Still a bug that would need to be fixed but at least we'd know exactly what to send to the BV Tech team.
If the gateway address setting proves to be correct, then either the phone isn't routing the traffic (perhaps like a firewall setting is misconfigured) or the service provider can detect you're using the phone as a hotspot and is blocking it. Of course the first one is a BV problem to fix, the second one, well, not so much.
But I think once we get the default gateway address from a connected device, compare it to the phone's address, and see that they're not the same, Admin should be able to forward it along to tech. At the same time, if this is the case, a workaround could be manual config on the connected device
Then again if the gateway address on the connected device matches the phone's address, and the phone is pingable from the device, while it could be an issue in the phone it still could be the provider (even if they allow hotspot use, some have been known to have misconfigurations on their end in the past).
This is the extent of my experience with the subject. I hope it's helped in some way even if I'm telling you stuff you already know (then again, maybe it helps someone else). Good luck!