Re: Roku Ultra does not show up on Windows 10 devices
Have you tried unplugging the Ultra and shutting down your laptops; then powering the Ultra back up and finally powering on your laptops? Do you have any problems with the remote connecting to your Ultra? I ask because both Windows 10 screen mirroring and the remote use a Wi-Fi Direct connection to communicate with the Roku.
You could try doing a network reset in Windows by searching for 'network reset' in the search bar. You can also do a network reset for the Ultra at: Settings > System > Advanced system settings > Network connection reset. Edit: For some reason when I tried this, I had to disable and then re-enable my wifi adapter in Device Manager to get my Roku to show up as a device.
If you're at your wits end, you could run Fresh Start on Windows 10 (search 'fresh start') or do a factory reset of the Ultra. These are last resort options though and there's no guarantee they would fix the problem. You'd want to back-up anything important (files, bookmarks, etc.) on your PC and would have to reinstall apps. On the Roku, you'd have to sign back in to apps and would lose any not-signed-in YouTube history.