i think it’s normal, happened to me with different devices

reflash the stock rom. google it

Did 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.