I would call.
I don't actually support the 75XX product, but I am in the room where they are supported, I've heard issues with 2012.
That being said, I did altboot (completely wipe) one, and we built a Server 2012 VM, patched it fully including the MS17.010 patch and scanned without issue from the 75XX with no issue at all. We did not disable SMB1 and we did not do a wireshark trace to verify what it did. So if you disable SMB1 and not just apply the patch that fixes the hole in SMB1, your results could easily be different.