Tethering Samsung s9 not seen

Just got my new glmt300n-v2. My phone hotspot is turned on, my phone is connected to the router via USB. When I go to the tethering tab I get the message that no phone is found. I have a Samsung S9. Help, please!

I googled and get this Product Help & Support | Samsung Australia

by the way, GL-MT300N-V2 already have v3.x firmware with more convenient UI, GL.iNet download center

I had a similar issue with my 750S slate router and a Nexus 5x. If I used a Anker USB3 type C data cable the router did not see my phone.

However using a non USB C certified cable (USB2 only) my phone was detected and USB tethering worked.

Strangely the tethering function does not work with any of my quality USB3 type C cables ! (Perhaps dure to the inclusion of tie-up resistors in the type 3 cables ?)

Hope this helps,