I have a Lumia 735 which is new and an HTX8x.
The Lumia connects to 2 WiFi SSID's I have here, but will not connect to other open hot spots, even though the HTC8x will.
Just tries for a bit "connecting" then message can't connect no response.
It was 4 different outdoor Hotspots put up by xfinity and one private one. 2 in my house which are secured work fine
After reading the VSZ and MSFT support sites, I rest the phone and now they seem to work pretty well.
One guess, it that it may be a problem with the WiFiSense option, which I have now turned off