WANTCOLUMNSANCHORED is desupported

In version 1.3x, the WANTCOLUMNSANCHORED attribute was undocumented but still supported by the language, to simplify migration from 1.20.

In version 2.0x, the WANTCOLUMNSANCHORED attribute is desupported; you must use UNMOVABLECOLUMNS to specify that table columns cannot be moved around by the user.