A slow room is not always an internet-plan problem. Wi‑Fi is radio, and radio performance changes with distance, building materials, competing networks and household electronics.
The objects that deserve the blame
Concrete and brick
Google notes that dense building materials can significantly reduce wireless speed and range.
Metal
Metal cabinets, appliances and other large metal surfaces can strongly block or reflect radio signals.
Mirrors
The metallic backing on mirrors can interfere with Wi‑Fi, especially when a large mirror sits directly in the signal path.
Floors and large furniture
Multiple layers of dense material and bulky objects add attenuation between router and device.
Some devices do not block Wi‑Fi—they compete with it
Google lists microwaves, baby monitors and other 2.4 GHz devices as possible sources of interference. Nearby Wi‑Fi networks can also compete for airtime, especially in apartment buildings.
Move before you buy
1. Put the router in a central, open position.
2. Reduce dense obstacles immediately around it.
3. Test the affected room closer to the router.
4. Only then consider additional mesh points, wired backhaul or other equipment.