Dummies guide to checking WiFi signal please!

I’ve used the broadband speed checker on Uswitch.

Try the Speedtest by Ookla app - recommended to me by BT engineer.

If you can hardwire to the router, your speed will about double.
Have you moved further away from the router, or is there anything metallic between you and it?
Signal strength may fall to a quarter if you double the distance.
The router should be strong enough. I used to be able to pick up the signal from my next door neighbour's!
Not knowing the password, couldn't get into it, although he did offer.
A metallic screen will effectively block the signal (Act as a Faraday Screen) Michael Faraday was so confident that he sat inside a metal cage while a Whimshurst machine fired huge great sparks at him. He emerged unharmed.

Firstly do a speed test via a mobile phone or any connected device.
If it’s low then on your router there will be a WPS button.
Press and hold for 3 seconds and release.
Wait 5 mins or so and hopefully it will have reset.
Check the speed again.

My WiFi signal is sometimes slow. The funny thing is that when I phone Virgin to inquire they always assure me that it’s all ok and then low and behold it’s back to normal. Funny that ?