iPad connected to iPhone's hotspot has no internet (same AppleID)

I'm trying to set up a hotspot for a relative. She doesn't have a reliable wifi access point in her office but does get pretty consistent 2-3 bar LTE.

I had the carrier enable hotspot functionality on her plan & it's now available in the settings on her phone. I can turn it on, enable "Allow Others to Connect", and put her iPad near the phone to receive the prompt to trust and auto-join. The connection appears successfully established as it now shows as the connected wifi network on the iPad, and the iPhone displays the green bar with the "1 device connected" message at the top of the hotspot page in the settings.

However, the iPad does not have internet. Any attempt to navigate to any website in a browser results in an error page stating there is no connectivity. Going back into the wifi settings page on the iPad reveals a never-ending spinning circle next to the network name.

I'm not an iPhone user so I don't know what to troubleshoot next. Things that I've tried so far include:

• toggle wifi on both devices
• power cycle both devices
• forget the network on iPad
• toggle "low data mode" in iPad connection details
• connect devices via Bluetooth before testing the hotspot
• disable Bluetooth on both devices before testing the hotspot

In addition to the troubleshooting steps above, I've also reset the network settings on both devices and rebooted. That reverted the iPhone's device name to default, so I changed it to a new name. The iPad is now showing BOTH hotspots. The OLD name shows the LTE connection bar indicator, whereas the NEW name shows no details. NEITHER will connect (same behavior as before).

I tried disabling WiFi and tethering via Bluetooth with the same results.

I was able to connect the iPad to my phone's hotspot (Pixel 5) just fine. It had internet access as expected. Tonight I will try connecting my iPad (Air2) to her iPhone hotspot to try and rule out her iPad as the problem maybe?

Here are the detailed specs of the 2 devices (both with the same Apple ID signed in):

• iPhone: "KatsPhone2" (new name after network settings reset)
  • iOS v16.5.1 (c)
  • Model: iPhone SE (2021)
• iPad: "Kats EyePad"
  • iPadOS v16.6
  • Model: iPad 9th Generation