QNAP, AD, and SSSD SID to UID/GID mapping

[Cryptic]

I have an AD domain with quite a few Windows hosts. I have a number of CentOS hosts using SSSD to auth against AD. I recently got some QNAP boxes that are AD members. I would like to get more QNAPs to replace various file servers, but there is an issue with SID to UID/GID mapping.

My user has an AD SID of:
(lots of numbers)-5891
CentOS translates this to a UID of:
1522805891
QNAP translates this to a UID of:
10005892

Now, you might think this is just an issue with 2 different clients translating the SID a little differently, but the significant identifier is one off on the QNAP. It is the same with all the users, and with the GIDs as well. That makes me think this is just broken.

Is anyone knowledgeable in this area that can tell me if this is broken, or if I can get the QNAP to behave differently? I'd look at "fixing" the CentOS clients to match the QNAPs, except that the QNAPs just look wrong.