In environments where there are multiple access points, the most recent update to the phone has killed the network access when it switches access point!! I have to keep turning off WiFi and turn it back on again.
Still okay, I did turn back on the "switch to mobile data" in the Intelligent WiFi with no change in connectivity. If I was to guess (and it would be a guess at this stage) I would say it was the phone call over WiFi that made the difference.
