Wi-Fi and the problems' firstly there are three (3) bandwidths, 2.4Ghz and 5.Ghz, and indeed now 6Ghz the 2.4Ghz has a longer range but slower and it is is more prone to interference from other devices as smart home appliances, baby monitor's, security camera's Bluetooth ,garage doors devices, so it takes a long time to deliver the service, so get lots of interference, the 5Ghz will work better, but only in very confined area's and closer to the Hub or Router, better for gaming and video conferencing ,so help with less interferance, the 6Ghz is the latest generation of the Wi-Fi standard but only 6E BUILDS ON Wi-Fi 6 can operate, which translates to new devices like the Apple iPad, and Galaxy s10 and a few others mobiles, so it is a bit complicated, basically 2.4Ghz goes through walls and 5Ghz stays inside walls, whilst the 6Ghz is only for very New Devices, for WIFI extenders the best I have used and still think they are very good, sir the TP-LINK MESH extenders easy to install and very clever and powerful, look at the link or watch the YouTube, hope this helps, try the TP-LINK MESH, you can add as many devices to suite your needs, click the link
, or look at Google for TP-LINK MESH.