What error are you getting? 

What address are you trying? 

No specific error just cannot load page

192.168.0.1

192.168.100.1

try a different pc? 

Different browser? 

Or following this guide: 

i have tried with my tablet, tried with the phone but none have been directly connected to the modem   getting a usb c to ethernet cable to try it directlly

I am looking at the workaround   Tks

Connect the modem directly to a ethernet port laptop or computer(preferably windows) and log in to 192.168.100.1 if still unable to login then follow the below step:

 Try factory reset the modem once and try to login again to GUI web portal 192.168.100.1

http://arris.force.com/consumers/articles/General_FAQs/SB6190-Factory-Reset