I had the exact issue on my HTC one after ujpdating the software. It appears that there is a new "feature" that if the connection doesn't detect internet access after 30 seconds it blocks that connection. Mine dropped after 30 seconds and then tried to reconnect after I closed the connect and tried to reconnect. Go into settings after that connection drops and then click on the connection. It asked my if I wanted to unblock the blocked connection. After I said yes, it worked fine from then on.