Microsoft has stopped Screen Mirroring on certain models intentionally, imo. The intention is to "encourage" we users to purchase a new or newer phone. So as of 7 weeks ago my perfectly functioning Samsung Galaxy 8+ has the "mysterious" Error Code 801 showing on my PC which no one seems to know what it means. Not even their own troubleshooter. The irony is that the feature worked perfectly for well over a year. 🤔 They also keep removing my rating post. This is my 3rd attempt.