So we've got a home network setup as follows:
ONT cat 6 cabled to Netcomm NF18ACV router
Router cat 6 cabled to UnifiUS-8-60W PoE Gigabit managed switch
Star configuration Cat 6 network cables. 3 are wall sockets, 2 are Unifi Inwall APs powered by the switch.
SSID for the Netcomm router and the 2 APs are the same with same password so devices can easily switch over when you're moving around.
Everything is working as expected, solid WiFi signals everywhere. We have a gigabit fibre connection and all wired PCs plugged into the wall sockets are speed testing at 900-1100 Mbps.
This is where the problems kick in. My wife and I have huawei P8 phones which are getting awful connection speeds even with solid signal. I can stand right next to the router and still get bad speeds. To clarify this, web pages take an age to load, if I run a speedtest (usually through fast.com) it sits on 0 for a long time then randomly jumps up to 20 or 30 then back to 0.
Apple devices don't seem to have as much trouble, ipads streaming TV seem to be fine. We also have a couple of SmartVUs which we use to stream live TV and they stream at high res with no problems. We had a visitor with a laptop that was speedtesting at 125Mbps.
So possibly just the phones? But other weird things:
Samsung smart TV which is cat 6 cabled to one of the inwall APs, streams 1080p content without issue. But whenever you open Plex initially it can't find the server and you have to try a couple of times to do it. This also happens on one of the PCs. The TV also seems to have trouble browsing the internet and if you run a speedtest with it it does the same thing that the phones do. Sometimes it has issues reloading or downloading apps.
Pretty unsure where to even start to diagnose this, any help would be much appreciated :)