I tried to use Screen Mirroring on Roku Streaming Stick Mod. 3600X from a Windows 10 PC. I followed all steps of an Article 208754928 “How do I use screen mirroring with my Android or Windows device?” (https://support.roku.com/article/208754928). After accepting a “Screen Mirroring Request” I saw a message indicating that my video is being played, and then nothing happens.
1) Reboot/restart your Roku & PC and try again.
2) Switch the Roku from 2.4Ghz to 5Ghz, or from 5Ghz to 2.4Ghz and try again.
3) Switch the PC from 2.4Ghz to 5Ghz, or from 5Ghz to 2.4Ghz and try again.
4) Reset the network connection of the Roku and or PC (Settings/System/Advanced System Settings/Network connection reset) and try again.