iCloud login with safari

Hallo everyone,

since upgrading to OS 10.13 I can´t login to iCloud.com with Safari. Trying to do so I am told that I have to get the permission and a code is send to my iPhone. Typing the 6 numbers of this code I am told that there is a problem and I cannot be connected.

It seems to be a Safari-problem, because login with Firefox and Chrome is possible without any problems.

How can I solve this problem.

Thanks to everyone

Andy