Why does this happen?
This problem was originally a design choice, a conscious decision made by Google to modify Android so that it does not pointlessly consume your battery when it has no reason to. The timeout feature included in Android’s portable Wifi hotspot is designed to turn off the hotspot when there is no device connected to it until a fixed amount of time. Creating a WiFi hotspot is a taxing affair for a phone and can drain your battery faster than you’d like it to. Hence, if your phone doesn’t detect any active connections for that fixed amount of time, it disables the WiFi hotspot to save up on battery.
How do I fix it?
Fixing this problem is as setting the WiFi Hotspot Timeout to a larger value(or ‘never’) ; locating this setting is the tough bit. Head over to the settings of your Android phone and go to Wireless and Networks > More settings > Tethering and Portable Hotspot > Portable WiFi Hotspot. Once here, press your menu button (usually three dots, or the ‘More’ button as shown in the screenshot) to reveal ‘Timeout Settings’. Once the dialog box appears, select the highest value you can (60 minutes, in our case) and that should do it.
We could not find this setting on our Marshmallow Nexus 5 so a supposition that this problem has been handled in a better manner in Android 6.0 Marshmallow should be fair.
Conclusion
Originally introduced as a feature, this setting might prove to be a paint-point for some users. Android 6.0 Marshmallow seems to have eradicated this pernickety detail. If you are still not able to fix the issue, feel free to get back in touch and we will help you fix the problem to the best our abilities. Happy internet sharing!
