WLAN Connection to my Android phone.

It will be worth checking that Mobile data is OFF. It sounds as if the phone lost wifi and went hunting for something else, maybe mobile access? As other devices connect to your router then you must go somewhere else, a bar or cafe, and try from there.
You are not alone, try this with Uncle G, android-causing-wifi-router-lockups

Many thanks Dave. Your comments are absolutely right.From what I can see a common problem with Android hence the iPhones are okay. Data is Turned off suggest we all go for a " roam " tonight to see if we can sort.

Maggie X