If now the name is SSL server Standard, then I know what causes the problem.
In server A, the the certificate for SSO is imported correctly,
In server B, it's not. the certificate exist in System PSE but not in SSL Server Standard.
That's the reason.
And I only to know why, but I think I'm not allowed to change this setting . Getting to know the whys are enough for me.
Thanks Donka for your help!