Hiya, A few months ago my laptop suddenly stopped connecting to the WIFI when it is out of the room where the router is. My flatmate doesn't have this problem so it's definitely an issue with my laptop. I've FOLLOWED advice off the internet and had my laptop cleaned and ran scans and nothing is helping. Please help! Thanks in advance!

Also it is an HP Laptop running Windows 10 if that helps.The laptop antenna has become disconnected.
The router should have a way of showing yu the signal level.
In the same room expect levels better than -40 d.

If the antenna is bad, the level will drop to near -80 db.
Otherwise a good machine can be two rooms AWAY and still HIT -75 db.
These are only approximations based on personal experience.

Here is a link that MIGHT help:
https://www.netspotapp.com/best-apps-to-measure-wifi-signal-strength-windows.html
Quote

Before you write an angry email to your Internet service provider, purchase a new router, or return your brand-new smartphone because of mediocre WiFi signal strength, you should first measure WiFi signal strength using a WiFi signal strength meter app.