Tablet, Android 6. Connects to home router but not elsewhere.

[Simon M1]

Recently at Sister's place and it would not connect, sometimes declaring 'not in range'. Phone and laptop, no problem. At ASDA, won't connect.
Tried resetting to factory.

Ideas will be most welcome.

I've had multiple Android devices but never this problem.

 

[belodion]

Welcome.

Has it ever connected to any WiFi?

 

[B. Diddy]

Welcome to Android Central! Which tablet do you have? What about public wi-fi hotspots, like at your local coffeeshop or library?

At ASDA, do you have accept the terms and conditions of their public wi-fi in a popup window first, and if so, is that not showing up on the tablet? Or does the tablet not even see the public wi-fi there?