Wifi disconnects from laptop when I use my mobile

Hello,

So for the past few months my internet at home has been really dodgy, (virgin media) i have realised whenever I using my laptop and then use my phone the internet is disconnected from both devices and i have to wait a few minutes before it works again.

For example if I am watching something on Netflix, I then pick up my phone, i don't even have to open an app - the wifi then disconnects from both devices and it won't connect for another few minutes.

I have had this wifi, which is usually extremely good for 6 years, and the phone for 2. Phone is a Samsung note 9, laptop is a Macbook Pro, the 2013 retina.

Can anyone explain this to me and why this has happened so suddenly?

Thanks for any help.