Has anybody encountered the same?
Only change was update of DSfW server to SP1 of OES2018.
In kdc.log it shows this error: "preauth (encrypted_timestamp) verify failure: ASN.1 structure is missing a required field"
What is really strange I can access all shares - even the sysvol share on the DSfW DC - if i map the shares manually. And interestingly Domain Logon does work for Windows 2000 member computers.
And according to the documentation joining a WinXP PC to the DSfW Domain is supported, which means Domain Logon from WinXP PCs is also supported.
I will probably open a SR after my August vacation - but I fear the result will be a change in the documentation to unsupported for WinXP member computers.