My 640xl sometimes will not share internet

[WPCentral Question]

This only happens say every fifth time but it is annoying and I have to turn it off and on to reset

 

[Ryan ODonnell]

Are you running Windows 10 Mobile?
If so, this is still a known problem on some devices.

I have a similar problem on my Lumia 535 where if I turn off mobile hotspot, I can't turn it on again until a phone restart.

If running Windows Phone 8.1, try a hard reset.