Hi The. I'm Greg, 10 years awarded Windows MVP, here to help you.
Try these fixes for the errors:
http://woshub.com/rdp-authentication-error-func...
https://www.wintips.org/fix-remote-desktop-conn...
https://blog.fmsinc.com/remote-desktop-authenti...
https://www.youtube.com/watch?v=rPeZu65Hr-E
Report back results for each step so I know what else to suggest.
Feel free to ask back any questions. Based on the results you post back I may have other suggestions if necessary.
______________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.