"Screen flickering at low brightness" için yanıti think it’s normal, happened to me with different devices
"Won't boot, keeps flashing boot logo" için yanıtreflash the stock rom. google it
"tablet wont authenticate with my broadband" için yanıtDid you check your wi-fi router or call your provider ? In order for the Internet to work well in the router, without failures, it is necessary that the fiber line is very stable. And this stability is very difficult to find. I also faced such a problem and searched for a long time for a provider that would provide a choice. And found, this is https://usave.co.uk/broadband/ . They have different packages with different speeds and different prices. After installation, everything worked very well. So I advise you to do the same. This is a good way out of the situation.