For anyone would have same problem, I called 16991 (not 16990) since they are responsible for the hardware. And there is no way to replace NOS router. You do need to use it. However, you can use new router as access point:

• Turn off internet from NOS router
• Connect new router with the NOS router via ethernet
• New router wifi is your access point for your devices now

It’s unfortunate but that how it’s now. 

Good luck

Thank you for your feedback, @EZ ALMAGHOUT.
Your sharing will certainly help other users who have the same issue.

Best Regards,

@EZ ALMAGHOUT In Portugal you are stuck with the router from the isp, and sometimes is really a bad option. Im stuck with a great wifi 6 router that is turned off by the NOS itself. Its what most people would call isp stupidity. I would like to know when costumers will have a router with opensync so it dont get wifi turned off and a become a paperweight.