Hopefully this might shed further light on the problem and lead to a resolution.

I have AMS pro 6.1.3 on a Samsung Galaxy S7 (running Nougat) and also on A Samsung Galaxy Tab A6 (2016) (running Marshmallow)

On my home network:
On the Galaxy S7 - Scan fails!
On the Galaxy Tab A6 - Scan succeeds

On my daughter’s network
On the Galaxy S7 - Scan succeeds
on the Galaxy Tab A6 - Scan succeeds