WAX210 Management UI Rejects Password

I am a new user of a WAX210 access point.  It is ethernet connected to my switch.  It provides wifi connectivity to my devices just fine.  What it does not do is allow me access to the management UI using any method documented in the owner's manual after the initial setup.

When I attempt to access the AP UI via entering its IP address into a safari or firefox browser on my Apple Mac Studio, I get a page showing a depiction of the WAX210 device and a prompt for the device password.  When I enter the correct password, set up via the first time use, I get an "Invalid password" response.  I am absolutely certain I am entering the exact password I entered when I first set up the AP.  I am not confusing management password and internet password.  I get identical responses when I access the UI via wifi, connecting to the Management WiFi network.  My iPhone sees the Management network, connects, asks for the network password and gets a wong password response.  

The firmware is 1.1.0.31 as indicated by the response screen when I first went through the initial setup.  I have done a couple of factory resets and went through the initial setup accordingly multiple times with the same result.  I've even made the management password as simple as it can be and still be accepted by the setup process - it's not possible I've mistyped.  

I've even done power-off/on reboots of my workstation and iPhone.   And even pulled the pug on the AP counted to 20 and plugged it back in.  Nothing seems to work.

What, probably stupid, thing have I missed or can try?   Thanks a bunch.