When a ward is not suggested then there may be an issue with the new address provided. If there is an apartment number, lot number, or some other identifier for the address beyond the number and street name it needs to be put in the "street 2" line. Also check the spelling of all street names.
I always use the
USPS Zip Code Lookup site to see what they have for the address I am entering to move the household or member to. Even though the USPS will put the apt #, lot #, and other address extensions on line 1, the move-out tool requires those to be on line 2, (street 2).