After hours of going in circles it turns out all I was missing was
TDS_Version = 8.0 in the DSN in my odbc.ini file.
I had specified it elsewhere, but it needed to be here, too, apparently.
Hope this helps some other poor soul.

After hours of going in circles it turns out all I was missing was
TDS_Version = 8.0 in the DSN in my odbc.ini file.
I had specified it elsewhere, but it needed to be here, too, apparently.
Hope this helps some other poor soul.