Hello!
From the information you provided, it seems that your PC meets the requirements for Miracast, but you are still experiencing issues. Let's try to troubleshoot this further.
First, let's address your assumption about the Wi-Fi dongles. Miracast requires specific Wi-Fi hardware and drivers that support the Wi-Fi Direct feature. Some older Wi-Fi adapters or dongles may not support it. To check if your dongles are compatible, you can visit the manufacturer's website or consult the product documentation.
Regarding your question about using Miracast over Ethernet, unfortunately, Miracast requires a Wi-Fi connection, and it does not work over Ethernet. Miracast uses Wi-Fi Direct technology to establish a direct wireless connection between your PC and the display device.
Now, let's explore some additional troubleshooting steps:
1. Confirm the compatibility of your display device: Ensure that the device you are trying to connect to supports Miracast. Check the manufacturer's website or user manual for information on Miracast compatibility.
2. Update the firmware of your display device: Sometimes, updating the firmware of your display device can resolve compatibility issues. Visit the manufacturer's website for instructions on how to update the firmware.
3. Check if Miracast is enabled in Windows: Go to "Settings" > "System" > "Display" > "Connect to a wireless display". Ensure that the "Wireless display" toggle is enabled.
4. Check if your firewall or antivirus software is blocking Miracast: Temporarily disable any firewall or antivirus software on your PC and check if Miracast works. If it does, you may need to configure your security software to allow Miracast connections.
5. Restart your router: Sometimes, restarting your router can help resolve connectivity issues. Power off your router, wait for a few seconds, and then power it back on. Once the router has restarted, try connecting via Miracast again.
If these steps do not resolve the issue, it may be worth considering alternative methods to connect your PC to your display device, such as using an HDMI or DisplayPort cable.
I hope these suggestions help you in resolving the Miracast issue. Let me know if you have any further questions or if there's anything else I can assist you with!