Recently started working from home so set up a new office space on the 1st floor of my house.

I can't run a wire up their ao took advantage of a tp-link 1000mb power adaptor to get that issue resolved, however I need a work phone hard connected in so bought a switch also so all is going well but now my wifi on both phones is almost unstable and seems to be having a very bad packet loss every few minutes.

I also have two wifi tvs on the same connection that are having no issues along with a ps4 and my girlfriend laptop that she uses to remote connect to work daily and they all seem to be working fine apart from the phones...

Any suggestions? 

EDIT: im currently on virgin media 3.0 hub but upgraded to 250-300mbs connection. So hoping the brute force approach may work.