BusinessPartner Synchronization- BP not created in S/4 Hana?

Hello together,

we have a problem with the Business Partner synchronization from SLP to S/4 Hana via CIG.

We have studied the SAP help info and still found a note for a correction guide that needs to be imported.

We have set the default properties to default and SLP parameters are also set to default.

Can someone possibly send me a link for a guide where he could make the experience that the SLP BP Synch works?

The SAP writes in a S-Note that the key mapping must fit.
Does anyone have a tip where/what/how I check this exactly in S/4 Hana.
We have not made any settings there, it is set by default. The synchronization did not work from one day to the next.

When we create a BusinessPartner in SLP and sync it also arrives in S/4.

In the SRT_MONI (monitoring) it is displayed without errors.
But the problem is that it is not created.

FYI-
We use CIG as a direct connection and the components are up to date.

I would really appreciate if you have a tip here or someone could describe their experience if they have already had a similar problem.

Best regards,
Julien