@Dany547 band2 and band3 are both DFS channels, I guess because of the DFS channel, so the AP will automatically switch the channel.

@Yannie thanks for the replay.

But if i set the 20Mhz channel width to 52 / 5260mhz, why does the AP switch to an inferior frequency channel? Isn't it suppose to switch to channels 54 (for 40Mhz channel width) and 58 (for 80Mhz channel width).  Because it doesn't make any sense.

Also in setting, the AP says that it operates on channel 52 / 5260mhz, but in fact its on channel 40 / 5200mhz

@Dany547 Because they all belong to band2, DFS is not meant to make your device automatically switch to a channel with a better signal. There is a faq on their official website, you can refer to it.

https://www.tp-link.com/en/support/faq/763/

@Yannie ow, i think i understand now.

If there is a radar signal nearby the WIFI AP will switch to a non-DFS channel for a period of time, then i experience the disconnection. The problem is that the channels 36 to 48 are super crowned in the apartment building that i live so i experience WIFI issues.

What may be a solution to this? (except wired connection)