2201166 - A SQL statement can not get correct Query plan - SAP ASE

The following SQL statement can not get a correct query plan:

DECLARE @dt_loop datetime
DECLARE @warr_gl_acct int
SET @warr_gl_acct = xxxxxx
SET @dt_loop = '7/13/15'

SELECT order_type
           ,sum(gl_amt) AS amt
           ,flag=2
FROM CIS..my_journal_entry 
WHERE gl_acct_no = @warr_gl_acct
GROUP BY order_type

SAP Adaptive Server Enterprise (ASE) 15.7 

optdiag, wrong, table scan, CR2201166, CR#2201166, 2201166 , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , BC-DB-SYB , Business Suite on Adaptive Server Enterprise , Bug Filed