I have been using sql linked servers for years - and they have been working fine..
But now when I try to run a query (on a machine with win10) using linked server I get this error:

"Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'".

If I then run the same query on my older machine without win10  I have no problems and never ever had any problems. 

And now the funny part begins: if I run the query from my old pc (logged on with same credentials) and then within 5 minutes run the same query from my win10 machine - there is no problem...

It's like if my old machine establishes a connection that is open for about 5 minutes and then times out. And my win10 machine cannot find out to establish that connection...

Any idea?