Hi there, none of the steps are working. There is a serious WiFi issue on this very expensive iPhone which shouldn't be there. Apple knows about this as personally, Apple has spoken to me and I have a case number and nothing has been done from November 2018 itself. They have taken all the diagnostics from my iPhone as well and nothing has been done in the preceding software updates to fix this issue.
Not even basic mirror feature works on the iPhone XS Max on my Apple TV, none of this happens on my 6S or the iPhone 7 plus or from my iPad. This is all because of the INTEL WiFi which Apple is using and we as consumers demand a fix immediately. This is not right for Apple not to address this issue and it's extremely urgent. Data transfers also are bloody slow. I have contacted Apple so many times with no proper resolution with regards to this iPhone issue. If Apple tells you its your Wifi in the house or office, well it's not. I have tried it in various locations and it's the iPhone XS Max. I hope Apple will read this and give a reply. First time after the launch of the Apple iPhone, I am not considering changing to an Android.