I Had the same problem, I had to restart my HTC One to re enable, or connect via WiFi.
Here is the solution HTC asked me to do: Clear the Cache Partition on the phone.
How to WIPE CACHE PARTITION on your phone process
How to WIPE CACHE PARTITION on your phone
*Note: Before starting with the process, please disable the fast-boot in your phone by going to “Settings, Battery [Power], Fast-boot” uncheck fast-boot.
1. Turn Off the phone
2. Press and hold the power key and the down volume key at the same time until the following screen shows up
3. Go to “Recovery” using the volume keys to navigate and to select press the power key.
4. Press power button to turn phone on again.
5. The display will change to update the symbol at the top. Momentarily will see a triangle with an exclamation mark.
Press and hold the volume up key and then the power key.
6. Navigate to "Wipe cache partition" using the volume button
7. Press the power button once
8. The screen will show yellow letters, then turn back blue.
9. Please go to "reboot now".
Press the power button.
10. The phone will turn off and on.
That fixed it for me.
[QUOTEshdo;49609062]Here is a riddle about Wifi.
In my Company we have a lot of different phones, tablets and laptops...
- we have all togeter 8 Cisco access points on 2.4Ghz...
3 of us have a HTC ONE, and 2 of those is Dual Sim version.
NOW, within 2-3 days one of the Dual Sim phones Loose Wifi and needs to be restarted in order to get it working again, while the other Dual Sim works perfectly day in and day out...
The last Htc One, have also no problems at all...
None of our other phones, tablets and so on have any wifi problems...
The two Dual Sim is even bought on the same day in the same store...
Same firmware and everything, we can´t see any difference...
What can be the problem with the one Dual Sim phone that loose wifi ??
To make it even more strange, the same user earlyer had a HTC ONE (the standard version), and that had the same kind of problems...
I can´t figure out what the problem is...
Pleace help me with suggestions and hints, and i´ll try them all one for one...[/QUOTE]