Looks like there's a bug an undocumented behavior change in SQL Anywhere 12, 16 and 17.

----------------------------------------------------------------
SELECT @@VERSION;
SELECT sa_get_table_definition ( 'GROUPO', 'SalesOrderItems' );

@@VERSION
'11.0.1.3158'

CREATE TABLE "GROUPO"."SalesOrderItems" (
    "ID"                             integer NOT NULL
   ,"LineID"                         smallint NOT NULL
   ,"ProductID"                      integer NOT NULL
   ,"Quantity"                       integer NOT NULL
   ,"ShipDate"                       date NOT NULL
   ,CONSTRAINT "SalesOrderItemsKey" PRIMARY KEY ("ID" ASC,"LineID" ASC) 
)
;

COMMENT ON TABLE "GROUPO"."SalesOrderItems" IS 
    'individual items that make up the sales orders'
;

GRANT SELECT ON "GROUPO"."SalesOrderItems" TO "GROUPR" 
;

GRANT SELECT,INSERT,DELETE,UPDATE ON "GROUPO"."SalesOrderItems" TO "GROUPRW" 
;

commit work
;
ALTER TABLE "GROUPO"."SalesOrderItems"
    ADD NOT NULL FOREIGN KEY "FK_ProductID_ID" ("ProductID" ASC)
    REFERENCES "GROUPO"."Products" ("ID")

;

ALTER TABLE "GROUPO"."SalesOrderItems"
    ADD NOT NULL FOREIGN KEY "FK_ID_ID" ("ID" ASC)
    REFERENCES "GROUPO"."SalesOrders" ("ID")
    ON DELETE CASCADE 
;

commit work
;
----------------------------------------------------------------
SELECT @@VERSION;
SELECT sa_get_table_definition ( 'GROUPO', 'SalesOrderItems' );

@@VERSION
'12.0.1.4231'

CREATE TABLE "GROUPO"."SalesOrderItems" (
    "ID"                             integer NOT NULL
   ,"LineID"                         smallint NOT NULL
   ,"ProductID"                      integer NOT NULL
   ,"Quantity"                       integer NOT NULL
   ,"ShipDate"                       date NOT NULL
   ,CONSTRAINT "SalesOrderItemsKey" PRIMARY KEY ("ID" ASC,"LineID" ASC) 
)
;

COMMENT ON TABLE "GROUPO"."SalesOrderItems" IS 
    'individual items that make up the sales orders'
;

GRANT SELECT ON "GROUPO"."SalesOrderItems" TO "GROUPR" 
;

GRANT SELECT,INSERT,DELETE,UPDATE ON "GROUPO"."SalesOrderItems" TO "GROUPRW" 
;

commit work
;
commit work
;
----------------------------------------------------------------
SELECT @@VERSION;
SELECT sa_get_table_definition ( 'GROUPO', 'SalesOrderItems' );

@@VERSION
'16.0.0.2344'

CREATE TABLE "GROUPO"."SalesOrderItems" (
    "ID"                             integer NOT NULL
   ,"LineID"                         smallint NOT NULL
   ,"ProductID"                      integer NOT NULL
   ,"Quantity"                       integer NOT NULL
   ,"ShipDate"                       date NOT NULL
   ,CONSTRAINT "SalesOrderItemsKey" PRIMARY KEY ("ID" ASC,"LineID" ASC) 
)
;

COMMENT ON TABLE "GROUPO"."SalesOrderItems" IS 
    'individual items that make up the sales orders'
;

GRANT INSERT,DELETE,UPDATE ON "GROUPO"."SalesOrderItems" TO "MODIFY_ROLE" 
;

GRANT SELECT ON "GROUPO"."SalesOrderItems" TO "READ_ROLE" 
;

commit work
;
commit work
;
----------------------------------------------------------------
SELECT @@VERSION;
SELECT sa_get_table_definition ( 'GROUPO', 'SalesOrderItems' );

@@VERSION
'17.0.7.3399'

CREATE TABLE "GROUPO"."SalesOrderItems" (
    "ID"                             integer NOT NULL
   ,"LineID"                         smallint NOT NULL
   ,"ProductID"                      integer NOT NULL
   ,"Quantity"                       integer NOT NULL
   ,"ShipDate"                       date NOT NULL
   ,CONSTRAINT "SalesOrderItemsKey" PRIMARY KEY ("ID" ASC,"LineID" ASC) 
)
;

COMMENT ON TABLE "GROUPO"."SalesOrderItems" IS 
    'individual items that make up the sales orders'
;

GRANT INSERT,DELETE,UPDATE ON "GROUPO"."SalesOrderItems" TO "MODIFY_ROLE" 
;

GRANT SELECT ON "GROUPO"."SalesOrderItems" TO "READ_ROLE" 
;

commit work
;
commit work
;