RAK 612 button not responding to AT commands

I have a couple of RAK 612 button pads that i’m having trouble configuring.
for instance

They were shipped as AS923 but need to be reset as AU915.

But I’ve had no success having them join OTAA (local Chirpstack instance running on RAK/RPi).

It looks like the region change is not sticking, and join mode is reverting to ABP:

at+version
OK2.0.2.2
at+set_config=join_mode:1
OK
at+get_config=join_mode
OK1
at+band=au915
OK
Join ABP…
Key1 long Reset…
Welcome to RAK_LB801
Join ABP…
at+band=au915
OK
Join ABP…
at+band
OKAS923

I appreciate setting changes require a reboot, but have tried resetting with AT command and long button press, with no change. Any clue as to what is happening?

One other anomaly: the device responds on reset with

welcome to RAK_LB801

rather than RAK612. Are they the same?

OK, no response from RAK.

Is this device no longer supported? Not clear why both there are two buttons for sales with ostensibly identical functionality.