And you see this 10.159.76.XXX ip address on the router's status page at the internet connection ? If yes -> you don't have public ip address. your mobile isp is using private ips for the customers

@wrzosw1 Do you have any firewall/antivirus on your computer ? Try to disable the whole antivirus thing, maybe that's what is blocking the access

it's not possible to restore the settings. Okay, try to open the obi webpage without the deco - connect your computer directly to your isp modem/router/bridge. If it's working without the deco - it's...

What's the public ip of the main deco ?

In my country (small country in Europe) none of the Mobile ISP's are using real public ip addresses. :( If you are lucky you can request a real public ip from your MISP.

https://www.tp-link.com/us/user-guides/archer-mr600_v1/chapter-13-tp-link-cloud-service#ug-sub-title-3 simple: unbind the other cloud id and your cloud id.