If you have a SSL certificate and want to replace self -signed certificate, please refer to the link below:
Replace RDP Default Self Sign Certificate
by default the local Remote Desktop Protocol will use the self-signed certificate…not one issued by an internal CA…even if it contains all the right information. If you want to use a certificate other than the default self-signed certificate that RDP creates, you must configure the RDP listener to use the custom certificate…just installing the cert isn’t enough.
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