AD-Account login on SMB doesn't work [QTS 4.2.6 build 20170905]

[tom_22]

Hi,

I am running QTS 4.2.6 "build 20170905" on a Qnap TS-559 Pro II. The Qnap is added to/part of an AD-Domain.
Since version "build 20170729" there seems to be an issue with accessing the SMB shares with any AD-Account. Login with a local NAS account works fine (w.g. admin).

The log.smbd doesn't give any hint (log_level=10). I have rejoined the NAS to AD and verified that the AD accounts show on the NAS, but accessing from Windows or MacOS still doesn't work.

Any thoughts?

Thanks,
Tom