Seagate External HDD won't show up

I bought my first mac about 3 months ago. It's a 13 inch 2017 model. I have macOS High Sierra as you can see in the picture attached.

I made a mistake buying the 128 gb model instead of 256, and I am running out of space. So I bought an external drive - Seagate Backup Plus Slim 2 Tb 2 days ago. Since then I am still trying to figure out why isn't showing on my mac. I am using a Sandberg usb-c hub bought a week ago from someone from facebook...

I have tried the following:

1. make sure that checkbox in the finder preferences about showing external drives was checked.

2. open disk utility to check if the drive was unmounted or had errors.

only the primary drives appear there. no sing of my seagate...

3. checked system information

4. install paragon NTFS for mac as shown on seagate support website, still nothing...

6. plug it in a PC where it's currently working with no problems and format it with exFAT, then plug it in back in my mac - still nothing.

7. tried with the charger on/off.

8. tried with a usb-c to usb adaptor - is working but my wifi connection is going down and I am unable to use it anymore. that's the main reason I bought the hub. ( I tried in the first week since I get the Mac book to connect my old external drive - 500gb Toshiba used on my PC with this dongle and the output was the same - the hdd was working but I lost the wifi..)

this is what I get from system information when the drive is connected with this adapter. the HD is mounted and appear in disk utility and finder too.