Could you try follow these steps:
1. Log in to the Web UI of the RUT850 device
2. Navigate to Network > Wireless
3. Add new Wireless AP like the image below:
4. Enable Wireless and Save.
5. Then the wireless preview will look like this:
New SSID: Teltonika_Router
6. Now navigate to Services > Hotspot you will be able to see this:
7. Just enable hotspot on the AP that you create for mine it is Teltonika_Router.
So you the RUT850 will be broadcasting two SSID at the same time one operating in hotspot and the other one
is operating like the normal WiFi Network.
Hope it helps