Question [Q] Remote Release doesn't find the wi-fi

I'm testing the Remote Release app on a Lenovo A2107A tablet and it reports "No wi-fi device was found..." and yet the tablet is connected to the DSLRController access point on the TP-Link TL-MR3040. The DSLRController access point is setup and working, the admin interface works and is set up as per instructions.

Camera: Canon D700 / T5i
TP-Link model TL-MR3040 version 2
Tablet: Lenovo A2107A stock (not rooted)

I'm following the instructions at: dslrcontroller.com/guide-wifi_mr3040.php exactly (as far as I know), and using the exact same access point, set up the exact way.

So, what am I doing wrong? What should I do right to make this work?

Thanks - Richard Ginn