I finally figured out a way to reliably connect iPhone hotspot to reach.
Make sure you turn off all “auto-join” to every other wifi in the list of known wifi’s on your phone.
Make sure the reach only has your iPhone hotspot remembered.
I wait until the m2 has flashed green 10 times. Then turn on the iPhone hotspot to make it discoverable. This method seems to work the first time everytime.
The iPhone dumps its own hotspot connection to the reach, in preference for any “auto-join” connection. This is a pain in the rear.
The only other way to reliably connect is to use two iphone’s and transfer the connection over to the iPhone hotspot.