Just got a new S9 Plus but the wifi speed is very slow. I normally get 200+ Mb/s on my 5 GHz channel using my iPhone or my PC. The Galaxy Plus only achieves 40 or so Mb/s.
It appears to be running at 2.4 GHz speed at both 2.4 and 5 GHz.
When I connect in settings, the phone states the speed checked out at 351 Mb/s but the actual speed is as stated above.
I've checked my router and it all looks OK and runs at the higher speed for other devices.
Samsung chat support just advised me that it was my ISP!
Any ideas please?
I had the same issue and here is what I did to fix it:
Hold down on the WiFi network and select network settings, then advanced options then IP settings and change it to static
Thank now is working on my s9+ finally had been trouble for more months and saw your message that I try it out is was super fast now
I haven't had any problem, only that the applications that work with the location always ask you to turn it on to work, for example, the weather app.