Brian Gaff laid this down on his screen :
Sounds like a bit of dodgy design then. I mean I suppose you would need some
kind of receiver for its frequency, but all you would be able to deduce as
that it was doing something. Cannot the web site use diagnostics to tell you
if its being received?

It's a free data logging site (Ubidots). Repeated requests to view data
simply lock you out until the end of the period, as happened to me
yesterday...

I was busy setting a wine batch up, put in the electronic hydrometer,
then needed some confirmation that it was working, before sealing the
ferment vessel lid in place. So I was repeatedly refreshing the web
site and locked myself out, until the end of the period. It accepts and
stores the data on the site, you just cannot view it until the new
period begins.