I've had a look at the Web Developer app and I can see a few errors there in the GetValue macro. Here's what I think is happening:
The first 3 icons initiate a Fetch for the page name to "getvalue" whereas your embedded app is looking for "getvalue.htm", so that Fetch returns with "unknown page".
The second 3 icons set the page name to "setvalue" but mistakenly set it for the wrong Fetch component (FetchForReadVal instead of FetchForReadVal1). The Fetch is then called for the correct FetchForReadVal1 component and this uses the hardcoded url set in its property (which is set to "
http://192.168.100.230/setvalue.htm").
The upshot of all this is that the first Fetch returns with a string ("unknown error") and Gauge1 is set to this value (which is probably zero). The second Fetch returns with your embedded Str2 string and this gets set on Gauge2.
Fixing the urls so they refer to "setvalue.htm" and "getvalue.htm" should fix it, but remember to also set the url for the correct FetchForReadVal1 component.