Hello,
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
Regards,
Jerome