Merge Queries in Power Query

Hello community, I have data as below,

Table 1:

Date                  AccountCode                            Value

Table 2:

Date               AccountCode                               Value

when I merge the above two tables using Full Outer join and Date, Account Code as key columns, I am getting weird output.

 I didn't understand why the query created extra rows. My expected output is:

Finally, I want to achieve, if the date is < today, then get value else Table_2.Value.

Please suggest me how to do this. TIA