WIFI suddenly can t receive a signal, and you have to get close to the router to have a signal, and

There is electromagnetic interference nearby, microwave ovens, cordless phones, walkie-talkies, etc. There is also the problem of channel contention, which can be tried on other channels. Nowadays, wireless routers are very common, and you may be using them upstairs and downstairs in your neighborhood, and the problem of channel contention is sometimes very prominent.

Solution: Set different channels and stagger them between channels 1 and 13. For example, 1 4 7 10 13To do this, talk to other route owners.

For example, if two same routers choose the same 6 channels, then the two routers may interfere with each other, affecting the quality of the wireless network, because the same frequency wave will have superposition and loss, if you change the channel, this will ignore most of the interference, improve the availability of the network. In other words, open up several different wireless channels, in case your neighbor uses the same channel as you, both of your networks will be affected, so you might as well change the channel.

See if there's anything wrong with your antenna.