Wifi continually disconnects and reconnects. How can I stop this?

[AC Question]

This Tab S is 3 weeks new. In last few days it has started to disconnect and reconnect to wifi continuously. A written notification appears at the bottom of the screen every 10 to 30 seconds. Very annoying. Any ideas why this has started? And how can I stop it?

 

[Rukbat]

1. If it's 3 weeks old it's under warranty, so why not let Samsung worry about it?

2. If you have a microwave oven near the phone, it might not be random - microwave ovens and wifi use the same frequencies. And a 1,200 Watt oven will overpower a 100mW wifi signal every time.