The post by the author of the software is here and has instructions and explains everything and has the link to download. There is free software called Amyuni USB Mobile Monitor that I found that took seconds to enable, then change the resolution in Windows Display settings, and the Teamviewer problem of showing 640 x 480 resolution was fixed. There are software virtual monitor emulators which I don't think were even mentioned, and some of them do not offer high resolutions, so they are not all created equal. The other posts give helpful information, but no solutions without having to buy a dummy display emulator. I run a headless Windows 10 server that has an NVIDIA Geforce 1050 Ti on my home network, so it's not only an AMD problem, and it's not only a display port problem because my system doesn't even have any. I just wanted to post here for anyone who might need a real solution to this problem. However, if the situation remains the same, you would have to keep the monitor on so that the OS recognizes the available resolutions for it.įor further questions, please do not hesitate to contact us again. This way, it would be possible that Windows assumes the resolutions that the monitor is able to handle even if it is off, although, we cannot guarantee this. You could alternatively try to install, if available, the drivers for the 4K Monitor, and then try to update it on the Device Manager so that it is recognized correctly by Windows, and not as a standard monitor. Please be advised that unfortunately, TeamViewer is getting the resolution that the Windows OS on the PC is offering, and that usually depends on what Windows is able to gather regarding the monitor that is connected to the system, therefore, if the monitor is not being recognized when it is off, Windows won't be able to offer other resolutions to TeamViewer.

Here's what AMD said about it.after trying to recreate the issue in their lab:

How to use anydesk without a monitor