Hi,
Can you tell me what OS you have the credentials provider installed on? And is the provider installed on the machine you're trying to RDP to, or on your client system you're connecting from?
If it's installed on something like Server 2016 or lower, I have seen a similar issue, although it works ok on Server 2019 and Windows 10. If it is an older OS and you want to use RDP, I think the only option for now would be to log on to the system via its console and uninstall the credentials provider.
Thanks,
Chris.