Radius certificate issue on Win10

[uj2.hahn at posteo.de]

I know, this is not really a freeradius tool question but more a Windows 
issue.
I created new radius certificates and installed them on server and some 
Android clients.
Everything is working fine. These clients can login without password now.
But not comes the real exercise: I tried to setup Win 10 (version 1909) 
clients to be used
in same way (login via certificate instead of user/passwd).

But something is completely wrong. I followed some guidelines I found in 
the web and created
a WLAN profile with the necessary setting.
But when I use the profile to open the WLAN connection, the only thing I 
see is something like:

"Connection is not possible, You need a certificate to login. Please 
contact your admin."

Is there anybody out there who can help me to resolve that issue?

Thanks a lot
Uwe