Personal Hotspot Won't Stay Connected iPhone 7 iPad Air 12.3.1

I have had a lot of problems recently with the personal hotspot from my iPhone 7 running 12.3.1 to my iPad air (6th gen) running the same ios. I have tried every single troubleshooting step to no avail. My iPad will connect to other wifi and other hotspots.

Problems that have occurred (at different times and sometimes at the same time) are:

• Connects for half a second (I can see the blue connection bar on the iphone) and then drops out. Over and over again.
• Says I have the wrong password despite being able to see the password on the phone. Also occurs when I share the password from the phone to the iPad.

With the last update, the hotspot seems to have moved from it's own separate "hotspot" part of the Wifi menu to just one of the list of many.

Steps I have tried include:

• restarting, including a hard reset of both devices.
• restoring network settings to factory.
• numerous variations of turning wifi on/off and hotspot on/off.
• connecting to other wifi
• typing in the password, sharing the password from the phone
• changing the password
• all other recommended troubleshooting steps.
• changing from manual to auto join and vice versa

Any more ideas??