Some 5 GHz Wi-Fi channels share spectrum with radar systems. Dynamic Frequency Selection, or DFS, requires compatible wireless equipment to check for radar and move away when it is detected. That can create a delay or interruption that looks different from a failed internet connection.

Establish what disappeared

Record whether the network name vanished from several devices, whether only one computer disconnected, and whether wired internet access continued. Note the time, router restart history and the 5 GHz channel shown before and after the event, if that information is available.

TP-Link explains that a device selecting a DFS channel can listen before it starts broadcasting there. During that period, clients may not see the network. The timing depends on the channel and applicable requirements, so do not assume every startup should complete within the same number of seconds.

During operation, detected radar can cause the access point to leave its current channel. A later connection on a different channel is useful evidence, but it is not proof of radar by itself. Automatic channel selection or a restart can also change the channel.

Match the event to the device's record

Inspect the router's available event information and official support guidance for its model. Preserve a relevant DFS or radar entry with its timestamp if one exists. If no such evidence is available, describe the observation as a possible explanation rather than a confirmed diagnosis.

The manufacturer may permit choosing a supported non-DFS channel for the installation region. Have the network owner assess that option if repeated documented events interrupt important work. Do not disable radar protections or change the region to expose channels unavailable to the local configuration.

After an authorised adjustment, observe the original workload over a representative period and compare the interruption pattern. Repeated factory resets erase useful settings and do not remove the conditions that triggered a legitimate DFS response. Keep a record of the final channel choice and the evidence that justified it.

References: TP-Link DFS explanation.