What means "The Mac is connected to another device using a temporary Wi-Fi connection"?

Does anyone know what means "The Mac is connected to another device using a temporary Wi-Fi connection"?

Second time already I saw the following icon in macOS control center:

According to this Apple support article, it means:

The Mac is connected to another device using a temporary Wi-Fi connection.

At the same time, I received the security notification from Ubiquiti (I use Unifi devices as router and WiFi APs):

Rogue AP Detected