Just a guess, but it could be the same reason that when you take the 'phone off the hook, without dialing, you get a message or a tone, which causes a fault which is retified by replacing the receiver and starting again.
Huawei P10 review
1995-2015: How technology has changed the world in 20 years
An overview: What leading creative agencies are doing to improve diversity
New iPad, iPhone SE & Red iPhone 7 on sale now
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.