@Shiro0: Shiro0 wrote @PavanR the reply that you provided is seems to be no resolution at all. does it mean nothing that TP-Link can do because it is a hardware defect? Can we get the refund if so?...

@Marvin_S : Please see this post for the troubleshooting steps performed so far: https://community.tp-link.com/en/home/forum/topic/703524?replyId=1478738

@Marvin_S Done. I have shared the previous case number.

Yes. Exact same thing happens to my router. Single device in router mode - no mesh - wired side continues to function normally. Everything normally for 2-4 days after a reboot before the WiFi SSID...

@MatthieuSG - was your issue with the SSID disappearing/WiFi dropping ever resolved? You are not alone. I got mine from Costco as well in Dec. 2024 and set it up in Jan. 2025. I had 1 SSID configured...